Abstract: To evaluate the safety level of the timber ancient buildings, grey whitenization weight function clustering method of timber ancient buildings was proposed in this paper. The safety of southern room, No114, Iingshui village was analyzed by the method. Firstly, different weight of sub-factors of each index was determined by using analytic hierarchy process (AHP). Then cluster analysis was made by grey whitenization weight function clustering method. Furthermore, safety level and subordination degree of timber building was confirmed according to the principle of the maximum of grey clustering coefficient. The results show that the safety level of the timber ancient buildings obtained by grey whitenization weight function clustering method has good agreement with testing result.