The calorimetry is commonly used for high-power laser power measurement, but the traceability is complicated. The high-power laser power measurement method based on principle of light pressure with higher measurement accuracy was introduced, the measurement experiment using a balance with an accuracy of 1/10⁵ was designed, the reflectivity and damage threshold of the mirror based on GaAs semiconductor materials were tested, and the properties of mirrors based on GaAs semiconductor materials were determined. Under ordinary laboratory conditions, the power measurement repeatability and linearity were obtained, and the feasibility of balance with an accuracy of 1/10⁵ for high-power laser measurement was verified. Through the experimental results combined with theoretical calculations, it is concluded that the upper limit of the measurement power of light pressure can reach more than 3×10⁴ W by using the balance with an accuracy of 1/10⁵.