In order to reduce the working envelope size of multi-node laser communication antennas and improve the motion control accuracy of two-dimensional tip-tilt mirror, a compact mirror assembly is proposed. A scheme of directly bonding between a high volume fraction Al-based SiC (SiC/Al) supporter and a H-K9L plane mirror is adopted. The thermal stability of the tip-tilt mirror surface shape is improved, and the distance between the tip-tilt mirror assembly rotation center and the mirror surface is shortened to 20 mm. The design of three-point thin ring is used on the bonding surface. The influence of the bonding stress on the mirror surface is effectively reduced on the basis of ensuring the dynamic stiffness of the tip-tilt mirror assembly. The results of finite element analysis show that the fundamental frequency of the tip-tilt mirror assembly is 1319.96 Hz. The tip-tilt mirror surface shape peak-valley (PV) value is better than λ/4 (λ=632.8 nm) and the root mean square (RMS) value is better than λ/22 in the working temperature range of (20±5) ℃. A ZYGO laser interferometer is used for testing the mirror surface shape, and the test results show that the PV value of the tip-tilt mirror surface shape is better than λ/4 and the root mean square (RMS) value is better than λ/29 in the temperature range of (20±5) ℃. These results are better than tip-tilt mirror surface shape RMS value of λ/15 and meet the laser communication antenna requirement.