The invention discloses a combined detachable isolation device for controlling infection in a hospital. The combined detachable isolation device comprises a T-shaped support, and an anchoring hollow tube is arranged in the T-shaped support; an anchoring balancing weight is arranged at the bottom of the anchoring hollow pipe through an annular pocket, an annular ferrule is fixedly arranged on the outer side of the T-shaped support, a plurality of clamping groove columns are fixedly arranged on the annular ferrule, and the two ends of each clamping groove column are both provided with a buckle ring; an isolation curtain movably sleeves the portion, between the two buckle rings, in each clamping groove column; suspension beams are fixedly installed on the top and at the bottom of each isolation curtain, and a dark-color glass curtain is installed between every two suspension beams; a plurality of sterilization devices are fixedly arranged between the dark-color glass curtains and the isolation curtains, and negative oxygen generating devices are further fixedly arranged between every two adjacent sterilization devices. The device can be combined and flexibly installed very convenient,is good in isolation effect, has multi-layer sterilization and isolation functions, and can completely prevent pollutants in an isolation area from leaking outwards.