In the process of laser mass transfer of MicroLED chips (size about $10 \sim 50 \mu \mathrm{m}$), extremely strict requirements are put forward for the alignment accuracy $(\lt \pm 500 \mathrm{~nm})$ between the chip carrier and the target substrate. Otherwise, the parallelism deviation and angle deviation between the chip solder joint and the target substrate will directly affect the product quality. To this problem, a large-stroke high-precision spatial attitude regulator based on flexure is proposed. Innovatively design a lever-bridge hybrid displacement amplification mechanism (LBDAM) with large displacement amplification ratio and high positioning accuracy. Static modeling and finite element analysis were carried out. Finally, an experimental system of spatial attitude regulator is established, and a closed-loop decoupling controller is built by kinematic inverse solution method and PID control method for the multiple-input multipleoutput coupling system. The performance tests of the motion travel and closed-loop positioning accuracy are carried out. The various experimental results indicate that the Z-stroke of the designed spatial attitude regulator can reach $250 \mu \mathrm{m}$, the closedloop repeated positioning accuracy is $\pm 100 \mathrm{~nm}$, and the closedloop deflection adjustment accuracy can keep within $\pm 2 \mu \mathrm{rad}$, which can realize precise adjustment of spatial attitude.