Microchannel plate (MCP) is an important compact two-dimension multiplier for parallel multiplication of charged particles. With the advantages of high temporal resolution, high spatial resolution, high electron gain and compact structure, microchannel plate has become an important potential readout device for cryogenic quantum computing, such as the quantum computation based on floating electrons of liquid helium surface. For the sake of ultra-fast reading, it requires the signal readout time is less than 10-5 s at a temperature lower than 30K in the cryogenic quantum computing. However, the bulk resistance of MCP multiplier became giant at cryogenic temperature for the property of huge negative temperature coefficient of resistance, almost 105 Gohm at 20K~30K, resulting in a readout time of 10-2 -1s at cryogenic temperature, which was one of the major bottlenecks for the application of MCPs in the cryogenic quantum computing. In this paper, the bulk resistance of MCPs in two different bismuth contents (1at%, 2.4at%) under the same hydrogen reduction temperatures (730K) were present as the surrounding temperature controlled from 300K to 20K. The cryogenic bulk resistance of MCP was only decreased into 24% with the increase bismuth content from 1at% to 2.4at%, while thereof the normal bulk resistance was decline into 5%. The normal bulk resistance reduced only in the manner of improving the conductivity of conductive layer, could also increase the temperature-resistance sensitivity of MCP, leading an even greater temperature coefficient of resistance, which deteriorated the stability of readout in the cryogenic quantum computing.