The floor heave mechanism of development roadway in Zhaogu No.1 Mine was analyzed,and the floor heave was considered as an extruding and flowing type.After two months of supporting in which high-strength anchor,steel network and cable was used for first supporting and a full-length closed ring support used for second supporting,in the development roadway the displacement at roof,floor and two sides was less than 30 mm,and the time of first repair was extended from 2 to 3 months to 10 months and above,so the regular production of the mine was assured.