On the basis of the gravity change data of the Hexi area in 2002 to 2003 and 2004 to 2005 years,the movements of the Huangcheng-Taerzhuang fault were inverted by use of the ant colony algorithm(ACA).The inversion result shows that the ACA can be used for solving the 3D slipe rate of a fault effeciently,and the result is in basical accordance with the result obtained with geological method.Moreover,the result shows that the slipe rate of the Huangcheng-Taerzhuang fault appears spatially unevenness.