The utility model discloses a public bus congestion <{EN0}>detection device, comprising a congestion detection module for detecting the congestion levels in various blocks and congestion information collection-transmission modules installed in all blocks in the bus. The congestion information collection-transmission module comprises a pressure sensor which determines whether people exist through the pressing of the bus passengers and a wireless transmission unit transmitting the pressing signals in a wireless mode; the pressing sensor is connected to the wireless transmission unit; the congestion detection module comprises a wireless reception unit used for receiving the pressing signals and an intelligent congestion detection unit which detects the quantity of the passengers in various blocks according to the pressing signals transmitted by the congestion information collection-transmission modules and determines the congestion levels in various blocks according to the preset thresholds; and the wireless reception unit is connected to the intelligent congestion detection unit. The utility model discloses a detection device for the congestion in the public bus which can detect the congestion levels in various blocks of the public bus and has a low operation cost.