In order to study the influence of the pump light source spectrum and the absorption spectrum of the gain medium on the output efficiency of light-emitting diode(LED) band pump laser, and to improve the output efficiency, the spectral information was introduced into the laser rate equations to establish the rate equations of the LED band pump Nd∶YAG laser. Theoretical analysis and experimental verification of LED band pumped Nd∶YAG laser were carried out. The Nd∶YAG laser was side-pumped by infrared LEDs. Under the pump energy of 9.1mJ, a 1064nm laser output with an output energy of 607μJ was obtained. The slope efficiency of this LED band pump Nd∶YAG laser was 15.5%, and the corresponding optical-to-optical efficiency was 6.67%. The results show that the calculated solution of the rate equations was basically consistent with the experimental output energy, which is helpful for the study of improving the output efficiency of LED band pump laser.