Abstract: In this paper, according to the analysis of the range and degree of coal seam thermal metamorphism caused by magmatic rock in No.2227 Face of 12 coal seam in Fangezhuang Coal Mine, the floating and sinking data and key indexes of natural coke and thermal coal in metamorphic coal samples are tested. In order to reduce the pollution of metamorphic coal to coking clean coal, the coal seam collocation is used to control the quality of raw coal into washing and the coal washing process to improve the proportion of first stage separation and reduce the proportion of second stage separation. The method can greatly reduce the pollution of metamorphic coal to coking clean coal, stabilize the indexes of clean coal, and at the same time, natural coke is selected into medium coal, which increases the economic benefits of enterprises. This paper has reference value for the removal of metamorphic coal caused by magmatic rock in coking coal mine by washing and reducing the impact on coking coal index, and has reference significance for the recovery and utilization of natural coke and thermal coal.