Abstract: The findings of the relationship between different high temperatures and the related physical properties are in general needed to be classified in the development of high-temperature geothermal resources and the disposal of nuclear waste especially on magmatic rock. The experimental tests on diorite specimens are carried out by measuring the physical properties before and after the high-temperature treatment, then how the temperature affects the physical properties of diorite is analyzed. The observed results indicate that: (1) The temperature threshold value of the impact of diorite physical properties is 600℃; (2) The rock structures begin to be destroyed at 800℃, and are completely destroyed at 1000℃; (3) The high temperature damage to the diorite structure is mainly represented by the following three behaviors: thermal rupture of most of the mineral, blurred quartz boundaries, and feldspar alteration; (4) The density and vertical waves decrease with the increasing temperature.