It is important to investigate the erosion depth and explore the tectonic—thermal history of orogenic belt by obtaining pluton’s crystallization pressure quantitatively. For the calc alkaline intrusions, the Al in hornblende barometry can be applied to estimate their crystallization pressure. The premise for choosing the different formula of Al in hornblende barometry is to content with their applicable conditions, otherwise the results will be meaningless. Accordingly, the Al in hornblende barometry cannot be used for estimating the crystallization pressure of A type granitoids, neither the metamorphic pressure of the rocks. Meanwhile, it is argued that the temperature correction of Al in hornblende barometer proposed by Anderson and Smith (1995) is unnecessary for the calc alkaline intermediate—acid intrusions which crystallization temperature are below 750℃. The exponential formula of Al in hornblende barometer proposed by Ridolfi et al. (2010) is suitable to estimate the crystallization pressure of the hornblende phenocryst in calc alkaline volcanic rocks. However, the Al in biotite barometer proposed by Uchida et al. (2007) cannot be used any way due to the lack of theoretical and experimental evidences. The regional variation of emplacement depth of the Xuejiashiliang— Heishanzhai composite pluton estimated by Al in hornblende barometry indicates the tilting of the footwall of Yunmengshan metamorphic core complex. The low angle normal fault (LANF, i.e. detachment fault) can be formed by the tilting of the high angle normal fault.