Three methods of hydroxylation of the microchannel plate substrate were studied. The water contact angle of the substrate surface of the microchannel plate after hydroxylation and the morphology change of the channel end surface were measured, and the hydrophilicity and corrosion of the microchannel plate substrate in various methods were analyzed. The experimental results show that the aqueous solution of ammonia and hydrogen peroxide does not greatly improve the hydrophilicity of the substrate surface, the NaOH solution has a corrosive effect on the substrate, and the hydrophilicity of the substrate surface treated with the piranha solution is significantly improved without corrosive effect. The effects of the immersion time and immersion temperature of the microchannel plate in piranha solution on the hydrophilicity of the surface were studied. The results show that with the increase of the immersion temperature, the water contact angle on the surface of the microchannel plate first decreases and then increases, and reaches a minimum value when the temperature is 80℃. The immersion time has little effect on the hydrophilicity of the surface of the microchannel plate. Finally, the surface hydroxylation process of the microchannel plate is determined as the immersion temperature of 80℃, and the standing time of 20~60min.