重力加速度是物理学中一个重要的力学常量，其测定方法有很多，在大学物理实验中常用到的测量方法是单摆法. 但实验原理仅研究了单摆摆球的运动，忽略了摆球大小、浮力、摆线质量等因素的影响，因此测量结果不够精确. 通过对引起单摆法测定重力加速度的相关系统误差进行修正，得到相对精确的重力加速度公式和相应的合成标准不确定度公式. 最后对测得的数据进行合理地分析和计算，最终得出较为精确的实验结果.

Gravity acceleration is an important mechanical constant in physics. There are many methods to measure the value of gravity acceleration, and the simple pendulum method is often used in university physics experiments. However, the experimental principle only studies the motion of the single pendulum ball and ignores the influence of the size of pendulum, buoyancy, cycloid mass and other factors, so the measurement results are not accurate enough. The relative accurate formula of gravity acceleration and the corresponding synthetic standard uncertainty formula are obtained by correcting the system error that caused in the measurement of gravity acceleration by the simple pendulum method. Finally, the measured data are analyzed and calculated reasonably, and the more accurate experimental results are obtained.