Gen. David C. Jones, Air Force chief of staff, yesterday denied charges that his service defied congress by continuing a computerized management system that lawmakers had ordered canceled.

"One mistake we have not made," Jones said in defending Air Force actions on the program called Project Max, "is to attempt to deceive the Congress." He said his service followed congressional guidelines but should have kept lawmakers better informed about the project.

Jones testified as the leadoff witness before the House Defense Appropriations subcommittee which is investigating charges that the Air Force went ahead with part of an $800 million project despite congressional orders to cancel it in 1975.

Rep. John E. Moss (D-Calif.) and Charles Rose (D-N.C.), in turning over a file of documents to the House and Senate appropriations committees on Project Max, said the documents suggested "a classic exhibition of contempt" by the Air Force.

Chairman George H. Mahon (D-Tex.) told Jones yesterday that he wanted to start the House investigation of Project Max by getting an overview from the Air Force's chief executive and would hold an in-depth hearing later. Subcommittee investigators will make a detailed report in the meantime, he said.

Jones said Air Force Maj. Gen. Robert L. Edge used a "poor" choice of words in writing a memo which said, "I'm not overly concerned about 'unapproved' work" on Project Max. Jones said Edge, head of Air Force computer resources, sought "to emphasize that the 'unapproved' work was, in fact, approved interim work, and that Congress should be informed of it."

Under subcommitte questioning, Everett T. Keech, assistant secretary of the Air Force for financial management, said he had not found any "formal communications" to Congress about Project Max that preceded recent subcommittee inquiries about that continuing work on it.

The Senate Defense Appropriations subcommittee is scheduled to question Edge and Keech on the controversial project today. Jones said the cost of Project Max, if it is completed, would total between $40 million and $45 million.