The utility model provides a physiosis formula expandable rock bolt pole, include: stock centrum, the body of rod, hollow tube, inflation shell, spacer, tray, nut. The front end of expandable rock bolt pole is the stock centrum, and the centre is the body of rod, and the hollow tube lies in body of rod middle position, and it has the spacer to distribute in the outside of the body of rod, the spacer is fixed in the body of rod according to certain interval on, has an inflation shell at the outside parcel of the body of rod, has tray and a nut at the afterbody of expansion link, is provided with the valve at the afterbody of hollow tube. Can the effective control anchor size of power, just so make the inflation shell extrude the soil body and reach anchoring effect. After the work, can retrieve the body of rod and recycle. The advantage that has simple structure.