The invention discloses a liquid expansion temperature controller. The liquid expansion temperature controller comprises a bracket, a first porcelain ring, a first wiring piece, a long elastic sheet,a second porcelain ring, a fixed contact piece, a second wiring piece, a third porcelain ring, a bone china mounting frame, a fourth porcelain ring and a bone china lifting mounting plate which are fixed through rivets in sequence; the lower end of a porcelain column props against the long elastic sheet; the tail end of the long elastic sheet is fixed with a short elastic sheet through the bone china; the free end of the short elastic sheet is positioned above the fixed contact piece; a mounting shaft is arranged at the extension end of the bone china lifting mounting plate; the mounting shaftis sleeved with a bone china lifting plate; the lower part of the bone china is mounted on the bone china mounting frame; the lower end of the bone china is in contact with the upper surface of the bone china lifting plate; the liquid expansion temperature controller also comprises a liquid temperature sensing pack; the temperature sensing pack is connected with a capillary tub; and the tail endof the capillary tube is sealed, and the capillary tube is positioned between the bone china lifting mounting plate and the bone china lifting plate. The liquid expansion temperature controller is simple in structure, accurate in temperature control, long in service life, stable and reliable, low in start-stop temperature difference, large in temperature control regulation range, high in load current, and convenient and low in cost.