The present invention provides a novel psicose epimerase derived from Flavonifractor plautii and capable of converting fructose to psicose. The novel psicose epimerase according to the present invention possesses an activity producing psicose by epimerizing the carbon-3 position of fructose, and has maximal activity for the conversion of fructose to psicose at a relatively high temperature and a pH less than or equal to neutral, has excellent thermal stability, and can mass-produce psicose from fructose in a high yield for a short amount of time. Therefore, the psicose epimerase according to the present invention is advantageous in the industrial production of psicose, and it is expected that the psicose produced thereby can be usefully utilized in the functional sugar industry and also as materials for health food, medicine, cosmetics, and the like using the psicose.