The paper studies the collapsing height of overburden rockmass at metal mine with dimensional analysis. The collapsing height is closely related to such factors as mining techniques, thickness of ore body, mining depth, tectonic stress, size of goaf, lithology of overburden rockmass, lithological structure, fault structure and time, etc. The statistics and analysis of the influential factors are carried out. The functional relation and dimensional matrix are established combining the engineering practices and dimensional analysis. The quantitative relations are set up among collapsing height H and ore body thickness d, mining depth h, tectonic stress ? h , size of goaf s, unit weight of rock ? , coefficient of volumetric expansion of rock k and coefficient of hardness f . The prediction relation expression of collapsing height is verified with practical engineering. The computed results of collapsing height are consistent with the measured results at an error of about 5.8%, which satisfies the engineering requirements. This method provides references for mining parameter selection under the mine water body, mine rockburst control and selection of mining techniques.