Low temperature polycrystalline oxide (LTPO) display technology is a new integrated display technology that integrates low temperature polycrystalline silicon (LTPS) and metal oxide semiconductors (MOS) to achieve high performance and low power consumption display solutions. During the LTPO integration process, hydrogen may diffuse from the low-temperature polysilicon layer to the metal oxide layer, resulting in device threshold voltage drift and deterioration of stability, affecting display product performance. The differences of hydrogen in LTPS and MOS devices and the effects of hydrogen on MOS devices are discussed in detail. Two types of hydrogen blocking methods for MOS devices are summarized: using different dielectric layers and ion doping technology. In addition, the paper also arranges the hydrogen barrier for LTPO devices to improve the stability and reliability of LTPO devices. Finally, the wider application of LTPO technology in the field of high performance display through hydrogen blocking is prospected.