The wavelength/temperature coefficient of AlGaInAs MQWs FP laser devices are measured by analyzing the wavelength changed with ambient temperature at the same heating power. Also, the wavelength of device changed with heating power under RT are measured, and the thermal resistance of device is calculated to be 183K/W. Then, the temperature stress storage experiment are carried out on the device, the results showed: a slowly increased of wavelength happened as the ambient temperature increased from 120℃ to 220℃; and, a obviously blue shifted of wavelength happened while the temperature arrived at 225℃, the wavelength of device shifted to 1 265 nm from 1 297 nm before experiment; as the temperature reached to 235℃, the wavelength of device shifted to 1 258 nm, and the mode spacing decreased from 0.92 nm before experiment to 0.84 nm, that the effective refractive index of optical mode increased from 3.66 to 3.77; finally, the device became failure as the temperature arrived at 240℃. The possible reasons were mainly due to the Al, Ga and In atoms in the waveguide, quantum well and barrier layers of epi-wafer migration and the composition of these layers changing under the high temperature stress. The results will more provide the foundation for failure mechanism analysis and performances improvement of device under high temperature.