The present application provides a servo motor drive circuit and a 3D printing apparatus, a motion controller is configured to send a drive enable signal to the timer; a pulse period providing unit is configured to send a pulse period value to the timer and the first comparing unit at beginning of each pulse period; the timer is configured to perform initialization in response to the received pulse period value during enabling of the drive enable signal, perform cyclic timing by taking the pulse period value as a timing period, and send a timing duration to the first comparing unit; and the first comparing unit is configured to acquire current level information that satisfies a preset duty ratio according to the preset duty ratio, the pulse period value, and the timing duration, and send a drive signal to a servo motor according to the current level information.