In order to determine sampling test plan of pass-fail product more easily and fast, the integral equations equal to the accumulation ones were put forward. Testing plan can be efficiently solved by using these equations on computer. The equality of these two kinds of equations was proved; The numerical algorithm of the integral equations solution was given. By comparing results, which came from the integral equations under different reliability parameters conditions, with corresponding pass-fail testing plans in national standard, it could be found that national standard neither accounted for actual risks of both customers and manufacturers, nor provided testing plans when risks of both sides were unequal. The determination principles of pass-fail sampling plan was proposed: pay attention to risks of customers and manufacturers and make samples least. An application example showed that this method could make reasonable pass-fail sampling plan with the use of these principles when any reliability parameters were given.