The invention provides an assemble line detecting transmission motor's forward transmission control circuit, which belongs to the technical field of assemble line detecting to ensure that the detected assemble line controls the convey belt to run according to the forward process. The present invention comprises a three-phase circuit breaker QS1, an AC contactor KM1, a single-phase circuit breaker QS2, a start button SB1, a stop button SB2, an intermediate relay K, a CD4017 pulse distributor integrated circuit IC1, a 74LS08 four-door integrated circuit IC2, resistors R1~ R10, a potentiometer RP, a capacitor C1, diodes VD1 ~ VD8, Zener diodes Vs1 ~ Vs6, an NPN transistor VT1 and a forward sequence indicator LED. The circuit of the invention can effectively ensure that the conveyor belt of an assemble line runs according to a set direction (motor phase sequence connection mode) so as to avoid production accidents caused by the reverse operation of the conveyor belt and serious economic losses incurred from these accidents.