The output characteristics of the dual-frequency laser (DFL) based on the Nd∶YVO4/Nd∶GdVO4 combined crystal have been investigated experimentally. In the experiment, the pump current at 14.5 A is set, the heat sink temperature of the combined crystal rises from 5 ℃ to 40 ℃ with 5 ℃ intervals, and a DFL signal with super-large frequency difference up to 310 GHz is achieved. The experimental results show that the DFL signal power has a negative correlation with the heat sink temperature. The fitting rates of the left and right peaks power with heat sink temperature are -0.0190 ℃-1 and -0.0082 ℃-1, respectively. The DFL reaches power balance at the heat sink temperature of 32.36 ℃. In addition, the experiment also shows that the wavelengths of the DFL signal are red-shifted linearly with the heat sink temperature increasing. The measured red-shift rates of the left peak and right peak are 9.70 pm·℃-1 and 6.12 pm·℃-1, respectively.