The utility model relates to an anti-blockage centralizer and relates to a bushing centralizing device. The centralizer comprises an upper hoop, a lower hoop, a plurality of rigid centralizing strips and bow spring sheets corresponding to the rigid centralizing strips. The top and lower ends of the rigid centralizing strips are connected with the upper and lower hoops respectively, through holes are formed in the rigid centralizing strips, the top and lower ends of the bow spring sheets are disposed between the corresponding centralizing strips and the upper and lower hoops respectively, and the bow spring sheets penetrate the through holes of the centralizing strips and are capable of sliding in sliding grooves in the ends of the through holes. By means of the centralizer, the ends of the bow spring sheets can slide to reduce the bow height after pressurization when the centralizer is put into the well and blocked, so that the centralizer can pass through the diameter shrinkage well section smoothly, the bushing is effectively prevented from being blocked when being put in holes, the central degree of the bushing in the well can be guaranteed, and the centralizer is widely applied to bushing centralizing of various straight wells, highly-deviated wells and horizontal wells.