The invention discloses a cylindrical gear pair quasi-static transmission error test bench, a test method and a data processing method. The cylindrical gear pair quasi-static transmission error test bench is characterized by comprising a loading component, a rotation locking component, a test bench support component, a driving axle component and a driven axle component. The driving axle componentand the driven axle component which are connected to each other are successively disposed on the test bench support component. The loading component is mounted on a driving shaft end in the driving axle component. The rotation locking component is mounted on a driven shaft end in the driven axle component. The cylindrical gear pair quasi-static transmission error test bench has beneficial effectsthat 1) the test bench has only one cylindrical gear pair and a support mechanism for the meshing transmission of the cylindrical gear pair, and is compact in structure, small in occupied space, and convenient to maintain; 2) the test bench is loaded by a weight and does not require driving equipment such as a motor, a magnetic powder brake and the like so as to save funds and shorten an equipmentprocurement cycle; 3) test measurement can be performed just by normally meshing and loading a gear equipped with a strain gage.