The invention relates to a harmless reclamation dry type sanitary unit and a solid-liquid separation method which are capable of efficiently and durably achieving solid-liquid separation. The method includes three steps of firstly, subjecting feces and liquid mixture in a treatment device to treatment with dedicated powder and then extracting liquid supernatant formed after flocculation is precipitated through a filter composed of a filter screen to a dehydration device; secondly, heating the liquid supernatant in vacuum in the dehydration device to partially become steam which enters a condenser to be condensed as water; thirdly, discharging the remaining liquid supernatant of high concentration into the treatment device for being mixed, collecting the solids after flocculation is precipitated through a collection device and packaging. The harmless reclamation dry type sanitary unit is specially used for achieving the solid-liquid separation method.