In order to explore the solidification effect of the new type of 4 # powder solidified agent developed by Chang'an University, the article focuses on the silt clay at Dingxiang County, Xinzhou, Shanxi and the preparation of the soil samples mixed only the new type of 4 # powder solidified agent developed by Chang'an University. Then the article conducts the unconfined compression strength test of different proportion and different maintenance period with soaking or nonsoaking respectively, and the influence regularity of different proportion and different age mechanical properties are analyzed. The experimental results show that the increase of the strength of solidifiedsoil increases with the proportion and then becomes slow in the early stage of the maintenance, and the growth trend is opposite in the late maintenance; The increase of the strength of low proportion solidifiedsoil increases with the maintenance period and then becomes slow, and the growth trend is opposite with high proportion. On the basis of considering the intensity effects of different proportion and different age, the strength prediction formula in accordance with the soil mechanics properties of solidified soil is established, and it is useful for the solidified agent in the engineering practice to carry out the exploration of the strength guarantee theory and experimental study.