In order to improve the acceptance temperature bandwidth of laser second harmonic generation, temperature insensitivity of laser second harmonic generation in LiB3O5 (LBO) crystal is proposed by using non-principal plane phase matching method. It is found that when using the LBO crystal for second harmonic generation of 1 064 nm laser, there is a phase matching direction that is not on the principal plane, and the temperature full width at the half maximum (FWHM) in this direction is wider than that in the conventional principal plane direction. In the experiment, the LBO crystal with a cutting angle of (θ＝58.4°, φ＝27.0°) is used for second harmonic generation of 1 064 nm laser, and the temperature FWHM is 76.0 ℃, which is 12 times the temperature FWHM of traditional principal plane phase matching.