Disclosed are a thermostat and a temperature control method thereof. The thermostat comprises an outer housing, an inner tank, and seals provided on the top and the bottom of the outer housing, wherein the outer housing is provided with a first temperature sensor (1), and a heat insulation layer is provided between the outer housing and the inner tank the interior of the inner tank is divided into a preheating section (4) and a heating section (5) by a baffle (3), a liquid feeding channel (6) successively passes through the preheating section (4) and the heating section (5), a preheating module (7) and a fourth temperature sensor (8) are provided on the bottom of the preheating section (4), and the heating section (5) is provided with a heating module (10) and a second temperature sensor (11) connected to the heating module (10) furthermore, the outer housing is provided with an MCU (2), the MCU (2) being connected with four temperature sensors, the preheating module (7) and the heating module (10) simultaneously. In the temperature control method, a control variable U is set and the U is corrected on the basis of the difference between the temperature of an electrode Tpower supply and a set temperature Tset so as to keep the temperatures of the preheating section (4) and the heating section (5) in the thermostat constant in order to provide a better ambient temperature for sample detection.Linvention porte sur un thermostat et sur son procédé de commande de température. Le thermostat comprend un boîtier externe, un réservoir interne et des joints détanchéité disposés en haut et bas du boîtier externe, le boîtier externe comportant un premier capteur de température (1), et une couche disolation vis-à-vis de la chaleur étant disposée entre le boîtier externe et le réservoir interne lintérieur du réservoir interne est divisé en une section de préchauffage (4) et une section de chauffage (5) par un écran (3), un canal dalimentation liquide (6) traversant successivemen
