The invention discloses an automatic walking type bridge floor heating device and a bridge floor heating method and relates to the field of bridge floor heating. The automatic walking type bridge floor heating device comprises a walking support, a drive device arranged on the walking support and a temperature adjusting device arranged on the walking support. Multiple walking wheels are arranged atthe bottom of the walking support. The drive device is connected with one walking wheel so as to drive the walking wheel to rotate. The temperature adjusting device comprises multiple heating pieces,a temperature sensor and a temperature controller. The temperature controller is connected with the temperature sensor, the drive device and the heating pieces and used for controlling and adjustingthe drive device and the heating pieces according to the bridge floor temperature detected by the temperature sensor. A bridge floor can be heated to increase the temperature conveniently and quickly.