The speed of mechanical parking equipment is one of the main parameters to be guaranteed during the design process,and it is also a major test item during the type test process.In response to the issue of excessive rated speed deviation found in a type test prototype of a vertical circulation mechanical parking equipment,in-depth analysis and discussion were conducted on the factors that can affect the operating speed in the transmission system and design calculations,and the main reasons for the excessive speed deviation were determined.The analysis methods and conclusions in this article provide references for the design,manufacturing,installation,repairing,inspection,and fault analysis of vertical circulation mechanical parking system.