A high energy laser beam sensor is developed using photoelectric and calorimetric compound method by temperature field calculation and structure design in order to measure long pulse mid-infrared laser. The sensor can measure the total energy and power density distribution. It is consisted of calorimetric pile, photoelectric and calorimetric compound detector array, temperature field sensors, analog to digital converter and signal processor. The sensor has the effective sensitive area of 12 cm×12 cm, the spatial resolution of 2.4 cm, and the temporal resolution of 25 Hz, with the total energy measurement uncertainty of less than 10% and the power density distribution measurement uncertainty of less than 7%. The experimental datas prove that the method can be used in high energy, large area and high spatial resolution laser beam measurement.