Built-in roller box cover and low-floor tramcar

The utility model provides a built-in wheel box cover and a low floor tramcar, which comprises a main wheel box cover, two framework assemblies, two handrail mounting seats, two grids and a skirting line, the main wheel box cover comprises two wheel box covers and a pedal which are integrally formed; the two framework assemblies are supported on the lower portions of the interiors of the two roller box covers respectively. The two handrail mounting seats are connected to the two roller box covers respectively, and handrail corner connectors connected with the handrail mounting seats are arranged in linings of the roller box covers; the two grilles are respectively embedded on the side walls of the two roller box covers; the skirting line is connected to the lower edge of the main wheel box cover. According to the built-in wheel box cover, the two wheel box covers are integrally formed into the main wheel box cover, the number of parts is reduced, follow-up rapid assembly is facilitated, the installation accum