为了寻找狐偃山岩体隐伏形态特征，基于侵入岩体侧畔煤层挥发分的空间变化特征，刻画侵入岩体在煤系地层中的隐伏形态特征机理；依据西山煤田狐偃山岩体附近469组煤层挥发分数据及前人研究结果，通过制作研究区内02^#、2^#、6^#、8^#、9^#煤层挥发分等值线图、垂直挥发分变化方向剖面图，研究了煤层挥发分与侵入岩体距离关系。结果表明：狐偃山侵入岩体侧畔依次出现接触变质带、恒温变质带、耗散变质带及正常煤带，岩体影响带宽度在7 km左右，其中接触变质带的宽度在1 km以内，恒温变质带宽度在4～5 km范围内，耗散变质带宽度在2～4 km范围内；狐偃山侵入体在煤系中的隐伏形态为一大型岩体，其中9^#煤层下伏有多个小型岩株，煤层自上而下遭受岩体烘烤影响的程度逐渐增大。

In order to find the hidden morphological characteristics of the rock mass in Huyanshan, based on the spatial variation characteristics of the volatilization of the coal seam on the side of the intrusive rock mass, the mechanism of the hidden morphological characteristics of the intruded rock mass in the coal strata can be described. According to the volatile content data of 469 groups of coal seams near Huyanshan rock mass in Xishan Coalfield and the results of previous research, the relationship between the volatile content of coal seam and the distance of the intruding rock mass was studied by making the contour map of the volatile content of the coal seam and the profile diagram of the vertical volatile change direction in the study area of 02^#、 2^#、 6^#, 8^# and 9^# in the study area, and the results showed that: contact metamorphic zone, constant temperature metamorphic zone, dissipative metamorphic zone and normal coal belt appeared on the side of the intrusive rock mass in Huyanshan. The influence belt width of rock mass is about 7 km, of which the width of contact metamorphic zone is within 1 km, the width of constant temperature metamorphic belt is within 4-5 km, and the width of dissipative metamorphic belt is 2-4 km. The hidden form of the intrusive body of Huyanshan in the coal system is a large rock mass, of which there are many small rock plants under the No.9 coal seam, and the influence degree of rock mass baking from top to bottom of the coal seam gradually increases.