A laser projection display device, relating to the technical field of laser, including a laser light source having a light source shell, an airtight device fixed on an inner wall of the light source shell, and a laser device provided in the interior of the airtight device. The airtight device having a sealing housing and a gas pressure adjustment structure, the sealing housing is fixed on an inner wall of the light source shell, the gas pressure adjustment structure is arranged on one side of the sealing housing, the sealing housing is communicated with the gas pressure adjustment structure, and the gas pressure adjustment structure is configured to adjust the volume of the airtight device.