Precision measurements of local gravitational acceleration variations are of great importance in geophysical surveys. With advantages such as cost-effectiveness and portability, micro-electromechanical system (MEMS)-based gravimeters have shown the potential for long-term gravity measurements. In this article, aiming to further improve the stability of the instrument, the design considerations and system evaluations of an MEMS gravimeter are presented. With a linear spring design for the silicon proof mass, a low natural frequency of Hz and a large linear range of mGal are achieved with an ultralow self-noise floor of Gal/ Hz@1 Hz. By implementing a vacuum chamber system, the pressure variation is reduced from hundreds of Pa/day in atmosphere to a linear variation of Pa/day. In addition, an active temperature control system can suppress temperature fluctuations by 2–3 orders of magnitude within the band from to Hz. The stability of the proposed MEMS gravimeter is demonstrated via long-term Earth tides observations within a 30-day time span, giving a correlation coefficient of 0.957 with the reference. An excellent bias instability of Gal is demonstrated within the 8–3000-s averaging time range, representing one of the best performances to date in terms of stability for MEMS gravimeters. This shows the potential of high-performance MEMS gravimeters for petroleum and mineral prospecting, seismology, and other geophysical applications.