The Senate approved a broad education bill yesterday that would renew and expand programs affecting most of the nation's schoolchildren, including the major federal program for disadvantaged students.

The measure was approved, 97 to 1, with Sen. Jesse Helms (R-N.C.) in dissent.

The Robert T. Stafford Elementary and Secondary School Improvement Act would renew federal education programs until 1993, increase spending for some of them and authorize several new programs. It is named after the Vermont Republican senator who is retiring next year.

Among other things, the bill would reserve some money under Chapter 1, the $4 billion program for educationally disadvantaged students, for school systems in high-poverty areas. It also reserves 25 percent of bilingual education funds for methods other than native language instruction -- compared with the 4 percent now set aside.

The House passed a similar sweeping education measure last spring, 401 to 1. Both houses also have passed education spending bills containing enough money to pay for the programs authorized in the education improvement acts.

The Senate adopted the improvement bill after accepting, 98 to 0, a Helms amendment to outlaw "dial-a-porn" messages over interstate telephone lines. Under current law, such services can be offered to consenting adults.

Barry Lynn of the American Civil Liberties Union called the Helms amendment "patently unconstitutional . . . . {It} merely tries to reduce the entire adult population of America to hearing what is acceptable to children."