An improved mercury-rich vertical liquid-phase epitaxy (LPE) technique is described. This technique achieves the growth of HgCdTe materials through the optimization of graphite boat design and the control of growth solution. By optimizing the temperature field with flow field simulation calculations, the material quality is significantly improved. The material′s thickness standard deviation is less than 0.23, and its composition standard deviation is less than 0.001. This technique successfully achieved the growth of multiple 36 mm×42 mm HgCdTe bilayer heterojunction materials in a single operation, with stable mass production. The obtained material meets the requirements for the development of large-array p-on-n infrared focal plane detectors in terms of key performance indicators such as thickness uniformity, doping concentration, and surface defects.