Two alloys of Ti-25V-15Cr-0.2Si and Ti-25V-10Cr-0.2Si with different content of alloying element Cr after different thermal exposure were studied. The results show that Cr could refine the grain of Ti-V-Cr bum resistant alloy, and strengthen its mechanical property at room temperature. With the decrease of Cr, the amount of the second precipitation phase is reduced and the thermal stability of alloy becomes better, which can be interpreted by the eutectoid feature of alloying element Cr in titanium alloy.