The invention discloses a multi-pipeline system suitable for an engine. The multi-pipeline system comprises a pipeline shell, a short supercharging pipeline, a long supercharging pipeline and an air channel switching valve, wherein the short supercharging pipeline and the long supercharging pipeline are arranged in the pipeline shell, and the air channel switching valve is used for switching the airflow direction of the short supercharging pipeline and the long supercharging pipeline. A cavity for changing the length of the long supercharging pipeline is formed between the short supercharging pipeline and the long supercharging pipeline. According to the system, the cavity is mainly used for changing the diameter of a cylinder body wound by the long supercharging pipeline, the total length of the long supercharging pipeline is changed without changing the total length of the cylinder body, and therefore good resonance effect can be obtained, and the torque of the engine can be increased.