With advancement in modern communication equipment, increasingly higher requirements are placed on clock source devices. These devices must exhibit the characteristics of integration and miniaturization while ensuring frequency signal stability. Microelectromechanical system(MEMS)oscillators, which conform to these requirements,are gradually replacing traditional oscillators as signal sources in electronic equipment.This study entailed the design and simulation of a type of MEMS oscillator wherein the core frequency selection device is composed of a Lamb wave piezoelectric resonator. Prior to its application to anoscillator circuit, the designed MEMS resonator was simulated and tested, and two methods to optimize its parasitic mode were devised. Thus, a Q value of 1 357.5 and series resonance frequency of 70.384 MHz were obtained for the resonator. The optimized resonator was applied to anoscillator circuit, and the output signal and phase noise of the oscillator were tested. Consequently, MEMS oscillators with an output carrier frequency of 70.58 MHz and phase noises of -64.299 dBc/Hz@1 Hz and -144.209 dBc/Hz@10 kHz were obtained.