The invention relates to low temperature resistance straw mushroom bacterial and a breeding method thereof, wherein starting bacterial library construction, straw mushroom protoplast preparation and mutagenesis, mutation bacterial library construction, and straw mushroom protoplast inactivation and fusion are performed to finally screen rearrangement bacterial with characteristics of low temperature resistance maintaining, no significant growth speed change, no significant colony morphology change and no significant color change to obtain the low temperature resistance bacterial, wherein the biological preservation number is CCTCC NO:M2013207. The low temperature resistance straw mushroom has the following characteristics that: normal fruiting can be achieved, genetic stability is good, mycelium has vitality after storing for 42 h at a temperature of 0 DEG C, a fruiting body can be stored for 28 h at a temperature of 10 DEG C, low temperature resistance of the straw mushroom fruiting body is substantially increased, and the difficult problem that the existing straw mushroom fruiting body can not subjected to low temperature preservation is solved so as to substantially increase a yield and quality of the straw mushroom, effectively expand the straw mushroom planting season, and improve economic benefits.