By using two equation models of high Reynola number K-?, this pape r makes research on the diameter of the Shadowless lamp in first-level clean op erating room from the two aspects of controlling the diffusion scope of the poll utants and guaranteeing the degree of turbulence, which is helpful to select the diameter of the shadowless lamp in operating room.

Objective To introduce a new field-based operating astral lamp.

The clean flow field in operating room which is equipped with no-lamp,traditional shadowless lamp or hollow LED shadowless lamp is modeled in three-dimensional and numerically simulated.