Abstract: To clarify the feasibility of the microbial fermentation bed in the large-scale piggery in hot summer,the dynamic changes of the environment parameters were analyzed.The environment data of large-scale piggery of microbial fermentation bed was collected continuously for 104 days from June 1to September 12,and processed with DPS statistics software.The results showed that the average indoor temperature was 29.3℃,average padded lining(20cm)temperature was 40.5℃,average indoor humidity was 78.0%,average ammonia concentration was 14.4×10-6,average CO2 concentration was 955×10-6.Benefit from the strong ventilation and cooling equipment,the average indoor air temperature did not exceed 30℃,the average ammonia concentration was below 20×10-6,the average CO2 concentration was below the level of 1 200×10-6.All the environmental parameters did not exceed limited threshold,and met the requirements of pig growth.Therefore,the microbial fermentation bed can be used safely and reliably for large-scale piggery in hot summer.Whereas indoor temperature and bed inner temperature(20cm)was positively correlated with the correlation coefficient 0.554 0,and the indoor temperature was negatively correlated with indoor humidity with correlation coefficient 0.433 3.The cluster analysis of the inner air temperature changes showed that the inner air temperature in hot summer could be divided into two groups closed to outdoor temperature area,which were high temperature zone ranged from 28 to 32℃ and low zone ranged 24-27℃.Indoor humidity,outdoor temperature,outdoor ground surface temperature,outdoor CO2 concentration were positively correlated(0.54*,0.54*,0.46*,0.44*,0.52*).