The utility model provides a novel passive form buffering is spacing device, it includes the base and installs constant breadth cam mechanism on the base, spacing, ball, two sets of energy dissipaterand energy dissipater fixing base, constant breadth cam mechanism includes the four sides frame and installs cam in the four sides frame, the cam with ball's nut is connected, and is two sets of energy dissipater installs respectively it is on the energy dissipater fixing base of the both sides of constant breadth cam mechanism, two sets of energy dissipater keeps away from the tip of energy dissipater fixing base do not with the both sides of four sides frame are connected, install for spacing the periphery of constant breadth cam mechanism, cam mechanism is in spacing restriction is down twosets of make straight reciprocating motion between the energy dissipater, ball keeps away from the one end of constant breadth cam mechanism is equipped with and is used for the night bolt subassembly be connected with building structure or bridge structures. A buffering limiting displacement that the novel passive form buffering is spacing device cost is low just to be had well.