The invention discloses a double-mode silencer structure of an automobile. The double-mode silencer structure of the automobile comprises a shell. The shell is internally provided with a first partition plate and a second partition plate in a spaced manner. A shell cavity of the shell is divided into a middle cavity body, a first cavity body and a second cavity body through the first partition plate and the second partition plate, wherein the first cavity body and the second cavity body are located in the two sides of the middle cavity body. The shell is internally further provided with a gas inlet pipe, a middle pipe and a gas outlet pipe at intervals. The gas outlet end of the gas inlet pipe and the gas inlet end of the middle pipe are located in the first cavity body. The gas outlet end of the middle pipe and the gas inlet end of the gas outlet pipe are located in the second cavity body. Waste gas in an exhaust manifold is led into the gas inlet pipe through a waste gas pipe, and then sequentially flows through the middle pipe and is exhausted out of the shell from the gas outlet end of the gas outlet pipe. The silencer structure further comprises a valve assembly. A power mechanism drives the valve assembly to form the local closing or completely opening action for a gas flow passage of the middle pipe. When an engine is in a low-speed rotation or idling state, only the local part of the gas flow passage of the middle pipe is closed so that the exhaust backpressure can be increased, and the combustion noise is lowered accordingly.