To solve the problem of slope caused by blasting vibration damage at a certain iron mine, YBJ-1 blasting vibration seismometer and CD-1 velocity-meter were used to observe the velocity of particle caused by blasting according to the rock properties and the scale of blasting. The spreading law of blasting wave in the iron mine were acquired to propose an effective method of controlling the maximum blasting vibration velocity, which will keep slope close to blasting area safe from blasting vibration damage. The vibration velocity was proved to be relevant to explosive quantity and the location of testing spot. The magnifying effect of velocity along the height of slope was proved to decline with the relative height increasing. In terms of control of the maximum explosive quantity at the same time and the millisecond delay interval, blasting vibration has been reduced at the ratio of 23.6% . 15 ms delay interval was proved to be rational through the experiments in an open pit.