The design is based on the MSP430F149 single chip microcomputer which is the core of the cartype fire fighting robot. It can find fire through the digital output of infrared flame sensor，then the robot adjust the direction of travel according to the collected signal，and avoid obstacles with infrared counter tube at the same time. The robot can estimate the distance between the robot and the fire according to the analog output of the infrared flame sensor，and detect ambient smoke concentration by MQ2 sensor. In addition，the design has liquid crystal display function, buzzer alarm function and LED lighting alarm function. The overall design has low energy consumption，low cost. Experiment shows that the robot can find the fire quickly and effectively，then put out the fire，which is suitable for the family, dormitory, gas stations and other small places.