The growth of pig not only depends on its gene, but also depends on its growing environment. The factors that influence the piggery environmental quality mainly include temperature, humidity, ammonia, hydrogen sulfide, carbon dioxide, methane, etc. In this research, six environmental factors were chosen and summarized as two significant comprehensive factors through factor analysis, which are gas factor and drying factor. And the cumulative variance contribution rate is 81.066%. The comprehensive evaluation results of factor analysis are: (1) Under the same condition, the increase of temperature leads to the increase of ammonia concentration in piggery; (2) With the increase of humidity, ammonia concentration increased in the piggery; (3) Compared with other gas pollutants such as carbon dioxide, methane and ammonia, hydrogen sulfide concentration is relatively low in livestock and poultry. The above conclusions are consistent with the relevant literature and the actual situation. Therefore, the factor analysis method is suitable for analysis of environmental quality in pig house. At the end, the comprehensive ranking of piggery environmental quality were given based on factor analysis, which would provide certain theoretical basis and reference value for piggery environment quality based on small changes in climate.