With the popularization of strip mining in fully mechanized top coal caving in China, gob side entry retaining technology of retaining coal pillar has become one of the main layout methods. However, some new surrounding rock control problems such as asymmetric behavior of ground pressure appear. On the basis of in-depth investigation and statistics, the deformation and failure time and characteristics of gob side entry retaining in fully mechanized top coal caving face under the conditions of wide coal pillar and narrow coal pillar roadway protection were elaborated in detail, and the causes of deformation and failure under the two conditions were further analyzed. The causes of asymmetric deformation and failure of wide coal pillar roadway protection were insufficient coal pillar width and asymmetric distribution of vertical stress; the causes of asymmetric deformation and failure of narrow coal pillar roadway protection were uneven distribution of horizontal stress and lateral abutment pressure caused by mining.