The invention discloses a multilane speed measuring and block port triggering device based on microwaves. The device comprises a power supply module, an upper computer configuration module, a microwave radar sensor, a signal processing module, a video configuration module, a video sensor and a display storage module. The invention further discloses a multilane speed measuring and block port triggering method based on the microwaves, which comprises the steps that S1, module configuration is performed, and a trigger position is set; S2, the microwave radar sensor scans a detection region; S3, a radar detects target information and performs judgment on an illegal act; S4, the video sensor snapshots; S5, the video sensor performs recognition on license plate, size and vehicle model information; S6, pictorial information of all vehicles is generated; and S7, platform storage and illegal act evidence collecting are performed. The method and the device disclosed by the invention ensure that one microwave radar sensor can cover multiple lanes, and each lane is equipped with video sensor coverage, thereby being high in economic benefit, and suitable for application and popularization.