The use of ultrasound for enhancement of various biotechnological processes has received increased attention in recent years. In agricultural science and botany study and application, much interest in the growth and secondary metabolites of plant, have been focussed on the use of ultrasonic stimulation. In order to simplify and reduce cost, meanwhile to generate a superiorly stabilized and accuracy ultrasonic for stimulating plant seeds, tissues and cells. This apparatus outputs different frequency ultrasonic through MAX038 function generator, the LM3886TF chip drives a 90 W power amplifier with sine-wave, which frequency test is finished by the AT89C52 microcontroler, and the frequency can be observed on LED display panel by 82C79 chip. This feedback control system should enable precise exert mutative stimulative frequency and stimulative time to improve multiple species plant growth, development and effect the secondary metabolite biosynthesis of cultured plant cell.