Abstract: Based on the causes of high falsework collapses in recent years, 20 kinds of human errors are presented. In-situ investigations of human errors were made during the periods of falsework assembling and concrete placement. The occurrence of human errors are given and some human errors with high occurrence possibility on thickness of a tube, the length of a vertical tube above the top of a horizontal tube and the tightening torque of a bolt were surveyed and analyzed statistically. The influences of some typical human errors on ultimate capacity are presented. The reliability of a falsework with multiple human errors is calculated and the influences on structural reliability are analyzed.