TC4 titanium alloy has a series of advantages such as excellent corrosion resistance, low density, high specific strength, good toughness and weldability, and plays an increasingly important role in the aerospace field. Based on the finite element analysis method, the temperature field of TC4 titanium alloy disc was numerically calculated by using the heat conduction equation. On the basis of analysis of the working characteristics of metal materials processed by pulsed laser, a thermal model that conformed to the actual processing characteristics was established, and the influence of the temperature field of TC4 titanium alloy with laser power, spot radius and laser pulse width was numerically analyzed. The results show that if the central laser wavelength is 1 064 nm, the laser power is 2 kW, the spot radius is 2 mm, the laser pulse width is 8 ms, the pulse repetition rate is 1 kHz, the diameter is 5.0 cm, and the thickness of 5 mm, the peak temperature rise of TC4 titanium alloy within 50 ms is 1 209.80 K. Under the same conditions, when spot radius is 1.5 mm, 2.0 mm, 2.5 mm and 5 mm, respectively, the highest thermal deformation of the end face of titanium alloy is 30.033 μm. The research results will provide a theoretical basis for laser processing of titanium alloys and accurate setting of laser processing parameters.