A closed cooking system, comprising a cooking cavity formed by means of a shell in a sealed manner and an ingredient feeding and cooking system, a cooking fume treatment system, a seasoning adding system and a flushing system which are constructed by taking the cooking cavity as a core in a combined manner, the ingredient feeding and cooking system, the cooking fume treatment system, the seasoning adding system and the flushing system being each mainly formed by connecting main cooking equipment arranged in an interior of the cooking cavity and accessory cooking equipment arranged at an exterior of the cooking cavity; the shell being provided with communicating openings which are corresponding to the main cooking equipment and adapted for communicating the interior and the exterior of the cooking cavity, and the accessory cooking equipment arranged at the exterior of the cooking cavity being connected with corresponding main cooking equipment arranged in the interior of the cooking cavity through corresponding communicating openings so as to achieve corresponding ingredient feeding and cooking function, cooking fume treatment function, seasoning adding function or flushing function; the cooking fume treatment system comprising a wok device arranged in the interior of the cooking cavity and a cooking fume treatment device (3, 3c) arranged at the exterior of the cooking cavity, a side wall of the shell being provided with a first exhaust port for connecting the cooking fume treatment device (3, 3c), and cooking fume generated by the wok device in a cooking process being gathered in the cooking cavity and exhausted to the cooking fume treatment device (3, 3c) from the first exhaust port to be treated; characterized in that, the wok device further comprises a wok (1, 20c) and a wok lid (12, 23c) for closing or opening the wok (1, 20c); the wok lid (12, 23c) is provided with a smoke outlet corresponding to the first exhaust port; the smoke outlet is communicated with a cooking fume inlet (31, 321c) of the cooking fume treatment device (3, 3c) via a cooking fume pipeline(121, 311c); the cooking fume generated in the cooking process with the wok (1, 20c) being closed is discharged to the cooking fume treatment device (3, 3c) from the smoke outlet to be treated; cooking fume escaping into the cooking cavity is exhausted to the cooking fume treatment device (3, 3c) from the smoke outlet to be treated when the wok (1, 20c) is opened; a side wall or bottom wall of the shell is provided with an exhaust gas return port communicated with a cooking fume outlet (32, 322c) of the cooking fume treatment device (3, 3c), and cooking fume exhausted after being treated by the cooking fume treatment device (3, 3c) enters the cooking cavity from the exhaust gas return port to be subjected to circulating cooking fume treatment so as to achieve zero emission of the cooking fume. the cooking fume treatment system comprising a wok device arranged in the interior of the cooking cavity and a cooking fume treatment device (3, 3c) arranged at the exterior of the cooking cavity, a side wall of the shell being provided with a first exhaust port for connecting the cooking fume treatment device (3, 3c), and cooking fume generated by the wok device in a cooking process being gathered in the cooking cavity and exhausted to the cooking fume treatment device (3, 3c) from the first exhaust port to be treated; characterized in that, the wok device further comprises a wok (1, 20c) and a wok lid (12, 23c) for closing or opening the wok (1, 20c); the wok lid (12, 23c) is provided with a smoke outlet corresponding to the first exhaust port; the smoke outlet is communicated with a cooking fume inlet (31, 321c) of the cooking fume treatment device (3, 3c) via a cooking fume pipeline(121, 311c); the cooking fume generated in the cooking process with the wok (1, 20c) being closed is discharged to the cooking fume treatment device (3, 3c) from the smoke outlet to be treated; cooking fume escaping into the cooking cavity is exhausted to the cooking fume treatment device (3, 3c) from the smoke outlet to be treated when the wok (1, 20c) is opened; a side wall or bottom wall of the shell is provided with an exhaust gas return port communicated with a cooking fume outlet (32, 322c) of the cooking fume treatment device (3, 3c), and cooking fume exhausted after being treated by the cooking fume treatment device (3, 3c) enters the cooking cavity from the exhaust gas return port to be subjected to circulating cooking fume treatment so as to achieve zero emission of the cooking fume.