The Nd_9.5Fe₈₄B_6.5 ribbons were prepared by melt-spinning. The effects of the chamber pressure and wheel speed on the magnetic property and microstructure of the Nd_9.5Fe₈₄B_6.5 alloy were investigated. A complementary relationship between the chamber pressure and the wheel speed in rapid solidification of melt-spinning is proposed. The values of thickness and magnetic property in the ribbon sample prepared at the chamber pressure of 0.03 MPa and the wheel speed of 19 m/s are similar to that in the ribbon prepared at the chamber pressure of 0.05 MPa and the wheel speed of 15 m/s. XRD and TEM results show that the ribbons prepared at two conditions have same phase constitution and similar microstructure. Our work indicate that the melt-spun Nd_9.5Fe₈₄B_6.5 ribbons with similar magnetic property and microstructure are obtained by controlling the chamber pressure and the wheel speed in rapid solidification, which can be used to serve as a guide in achieving permanent materials with good magnetic property in mass production.