The invention provides a pressure measuring apparatus for a steel rail grinding head. The pressure measuring apparatus mainly comprises a pressure probe assembly, two rotating shaft sets and a pedestal assembly, wherein the inner axle seat of the pressure probe assembly and the rotating shafts of the rotating shaft sets realize shaft-hole connection. A shaft fixing plate and an adjusting spindle sleeve realize axial positioning of the rotating shaft on the inner axle seat, and the rotating shafts of the rotating shaft sets and the axle seat of the pedestal assembly realize shaft-hole connection. The shaft fixing plate and the adjusting spindle sleeve realize axial positioning of the rotating shaft on the axle seat. The pressure measuring apparatus effectively meets the actual requirement for measuring actual pressure applied on a steel rail head by a grinding wheel of a grinding head, when the grinding head on a steel rail grinding technology testing bench is at different included angles to a vertical line, and measures the actual pressure applied on the steel rail head by the grinding wheel of the grinding head under different included angles. The measured values provide decision making basis for controlling the pressure applied by the grinding head, correcting the pressure applied by the grinding head and determining the grinding process parameters.