Inorganic heat pipe is a new kind of heat transfer elements. To research the condensing characteristics of inorganic heat pipe condenser under negative pressure, the test-bed is established. In condenser design, traverse baffles are used to enhance steam velocity and steam disturbance to liquid film to strengthen heat transfer. Orifice connected to vacuum pump is fixed on the underpart of condenser to prolong steam flowing path and avoid steam loss caused by pump sucking. The relationship between water output and absolute pressure is a quadratic curve. The differences between testing water outputs and theoretical ones are analyzed. The research supplies a design basis for the inorganic heat pipes condenser used in low temperature distillation desalination unit.