Recently, there are many researches that are performed for increasing reliability about product life cycle using ALT(Accelerated Life Test), AST(Accelerated Stress Test) and ASA(Accelerated Stress Audit) in the industry. The test of this research needs a device that has wide-band frequency vibration. But most test devices such as HALT only show the good response of high frequency area. In this research, the platform of ALT was developed based on Stewart Platform using pneumatic Actuators. Pneumatic Actuators represent response of wide-band frequency by motion and mpact. Cylinders of Stewart Platform is operated based on frequency and pressure. This research shows system characteristic of Platform to develop the control algorithm of accelerated life test platform in future research.