Silencer for small gasoline engine

A silencer for a small gasoline engine comprises a shell formed by buckling a front cover and a rear cover. A catalytic agent positioning plate is arranged between the front cover and the rear cover, and divides an inner cavity of the shell into a front cavity and a rear cavity. The part, located on one side of the rear cavity, of the catalytic agent positioning plate is provided with a catalytic agent box. The catalytic agent box is internally provided with a catalytic agent cavity used for containing a catalytic agent. The rear cover is provided with a waste gas port for feeding of waste gas, the waste gas port communicates with the rear cavity, and the catalytic agent box communicates with the front cavity. The front cover is provided with an exhaust pipe for exhausting of gas. The inlet end of the exhaust pipe is located in a front cavity, and the inlet end of the exhaust pipe is sealed. The outlet end of the exhaust pipe is located outside the shell and communicates with the outer portion of the shell. A