The invention belongs to the technical field of indoor air environment purification, and particularly relates to a positive and negative pressure conversion movable sickbed, which consists of a sickbed, an air purification device, a fan, an air distribution pipeline system, an electric control valve system and an isolation system, wherein four bed legs of the sick bed are provided with wheels, the sickbed can be used as a moving sickbed or a fixed sickbed, the sickbed can realize the positive pressure air supply and negative pressure air suction functions, air distribution openings of an air distribution system are arranged on the head part of the sickbed and the tail part of the sickbed, the air distribution pipeline system is paved along the bottom of a bed plate and is connected with the air purification device through the electric control valve, the control system controls the fan to do positive rotation, the positive pressure air supply can be realized, clean air is provided for patients with the requirements, the fan is controlled to do reverse rotation, the negative pressure air suction can be realized, air with pathogenic bacteria breathed out by patients are collected in time, and in addition, the air is exhausted after the sterilization and the purification. The positive and negative pressure conversion movable sickbed has the advantages that the design structure is compact, other functions such as sickbed ascending and descending and the like cannot be influenced, the noise pollution is avoided, the energy consumption is low, the dust removal, sterilization and purification effects are obvious, and the positive and negative pressure conversion movable sickbed is suitable for being used as an ordinary sickbed or emergency sickbed for patients to be isolated in occasions such as hospitals and the like.