The energetic polymer glycidyl azide polymer (GAP) is selected as the propellant of laser ablation micro thruster, and the effect of infrared dye doping on the propelling performance of laser ablative GAP is analyzed. By comparing the propulsion performance data with the plumes of infrared dyes doped GAP under different laser intensities, doping concentrations, target thickness and laser ablation modes, the optimization of the propulsion performance of infrared dye doped GAP is explored preliminarily. The experimental results show that the exponential attenuation characteristics of laser energy and the strong viscosity of GAP doped with infrared dye in the transmission mode lead to the existence of incomplete ablative GAP in the plume. The propulsion performances of GAP are influenced by the doping concentration of infrared dye and the thickness of propellant. Only when the target thickness is close to the laser absorption depth, can the mass of incomplete ablation along the direction of laser propagation be the least and can the laser energy be fully absorbed by the propellant to make the central ablation region reach the temperature threshold of the release of chemical energy. At the same time the optimum value of propulsion performance can be achieved. The GAP doped with infrared dyes in which laser ablation process follows the rule of absorbing laser energy first and spraying first is decomposed adequately under the reflection mode and the propelling performance is better than that in the transmission mode.