In order to use of the outdoor cold climate resources as the low-temperature reaction condition, the objective of this research was to investigate the effect of freeze-thaw treatment (Z groups: -4℃, S groups: -20℃) on the efficiency of hemicellulose degradation and enzymatic hydrolysis pretreatment of rice straw to improve its biodegradability and anaerobic biogas production. A new low temperature freeze-thaw pretreatment development pathway was created for the pre-processing research and development. The results showed that water holding capacity was optimal when soaking temperature was 30℃, time was 4h, and liquid-solid ratio was 15mL/g. Under low temperature freeze-thaw condition, the contents of xylose in the liquid hydrolysates were increased (Z3: 6.5g, S2: 7.2g), hemicellulose conversion rate reached 24.1% (Z3) and 26.6% (S2), which were improved significantly（p<0.05）. Glucose yield were increased (Z3: 13.5g，S2：14.5g) after enzymatic hydrolysis, cellulose conversion rate reached 30.9% (Z3) and 33.2% (S2), which were improved significantly (p<0.05). These treatments conditions resulted in the highest total biogas yield (543mL, S4), compared with the CK, the total biogas yield from S4 was improved by 73.5%. The highest average methane concentrations level was 51.3% (S2), compared with CK, it was improved by 160.4%(S2）. Extension of time for freeze was apt to shorten the anaerobic fermentation period in the next anaerobic digestion. The digestion time for pretreatment rice straw (Z groups freeze-thaw treatment time was above 48h，S groups freeze-thaw treatment time was above 24h) was calculated as 19d, and the peak values of gas production came earlier than those of other groups. The significant reduction in digestion time indicated that the straw had become more accessible and more readily biodegradable after biological pretreatment. Freeze-thaw and enzymatic pretreatment could be an effective method for improving biodegradability and enhancing the highly efficient biological conversion of rice straw into bioenergy.