Faced with a refugee crisis of desperate proportions in Southeast Asia, and with increasing numbers of people fleeing various oppressive governments throughout the world, the Carter administrtration is readying a comprehensive reform of the nation's refugee laws to be presented to Congress early next year.

Current laws dealing with the admittance of refugees to the United States date from the height of the cold war and have proved, in the words of Sen. Edward M. Kennedy (D-m/ass.), both "inadequate and disctriminatory" in light of recent world developments.

The result has been a series of ad hoc executive and congressional measures haphazardly precipitated by one crisis after another over the last 25 years, congressional staff members asserted.

According to sources in the State and Justice departments, the new bill will in all likelihood provide for a "normal" annual flow of 50,000 refugees a year into the United States. Under current law, the number of refugees who can be admitted under normal procedures is 17,400 annually.

Another part of the proposed law, according to these sources, will enable the administration, after mandatory consultation with Congress, to admit numbers of refugees exceeding the normal flow in the light of such emergencies as the current Indochinese crisis. As the draft of the bill now stands, no specific limit is set on the number of refugees who can be admitted under such circumstances.

Under the proposed bill the functional definition of a refugee would also be changed to bring it into line with that of the United Nations protocol on refugees acceded to by the United States in 1968.

At present the only people who may be admitted under what is known as the "conditional entry" provision of the immigration laws are those fleeing Communist regimes or the Middle East. As a result it has been extremely difficult in the past for refugees from right-wing oppression to obtain asylum in the United States.

The new definition will apply world-wide to anyone who is outside his country and unable or unwilling to return because of persecution or a well-founded fear of it because of his race, religion, nationality, membership in a particular social group. or political opinion.

In addition, the attorney general would retain his authority to "parole" in people who would not otherwise qualify as refugees. But this practice would be much more limited than it has been over the last two decades.

Because of the inadequacy of the current law to meet the global situation the parole authority has been used as the United States' primary means of dealing with crises.

According to the U.S. Immigration and Naturalization Service, nearly 750,000 refugees -- including Hungarians, Cubans, Chinese, Russians, and 191,000 Indochinese -- have been "paroled" into the Unite States during the last 25 years.

Attorney General Griffin B. Bell told the House Judiciary Committee last week that he is "not comfortable about the use of the parole authority, which he said was originally designed to provide a safety valve for "unusual individual cases of compelling need that could not otherwise be met. It was not to provide the means to end-run the other provisions of the immigration law.

"And yet," Bell continued, "we are repreatedly forced to do just that because the refugee provisions of the law are inadequate to circumstances as we find them around the world and to our policies as a nation in attempting to respond.

Officials in the State and Justice departments stressed yesterday that the administration's bill is not yet in final form, though basically it sets forth policy provisions determined by the president last spring and addressed in testimony of administration officials before the House Immigration Subcommittet in April.

It may be modified after further consultations with interested members of Congress, including Kennedy, who has been pushing for a reform of refugee laws since 1966. A meeting of representatives of more than 40 governments in Geneva next week to seek international cooperation on the refugee problem also may result in some changes, these sources said.

The basic outline and aims of the legislation, however, are close to completion. As one Justice Department official familiar with the bill said: "It's basically a question now of dotting the i's and crossing the t's."

Kennedy has consisterntly advocated legislation designed to improve the equality and organization of resetlement efforts on behalf of the various groups of refugees that come to the United States. Administration sources said last week that they are working along similar lines, though the actual drafting of such bills is not as well advanced as the new provisions for admitting refugees.