The design of mirror house at home and abroad has been reviewed simply in this paper. A new consideration for design of the house is proposed, analysis of the chief characters and application vista are given. According to the optical principle of the streak camera, the coordinate equations of the image point have been derived before and after the plate glass is added. Since the plate glass is added, the writing rate of the image on the film track is given. The calculation indicates: the larger relative aperture of the instrument, the thiner plate glass is allowed, the rigorouser the requirement of axial displacement. When mirror rotates, the J-curve of the axial image points for different relative aperture is shown. Proceed from actual instrument, the performances of the instrument using a spherical corver or plate glass are compared. The defocusing dS' is a critical data for streat camera, it will directly affect the imageing quality of the instrument.