The invention discloses an immobilized nitrobacteria enrichment culture method and device in a sewage treatment process. A sequencing-batch biomembrane activated sludge process is utilized to perform enrichment culture on nitrobacteria: dewatered sludge is inoculated in an immobilized nitrobacteria culture device, and an enrichment culture solution is added; and in the nitrobacteria enrichment culture process, the biomembrane ammonia nitrogen load is gradually enhanced, and the pH value is controlled. The enrichment culture solution is formed by mixing NH4HCO3 and pretreated municipal sewage, the ammonia nitrogen concentrations are respectively 100, 300, 500, 700 and 1000 mg/L, and the COD (chemical oxygen demand) concentration is 30-60 mg/L. By controlling the immobilized nitrobacteria culture device, the DO in the reaction mixture is 2-6 mg/L, the pH value is 6.5-8.0, the biofilm-formation acclimatization culture temperature is 10-14 DEG C, and the enrichment purification culture temperature is 15-25 DEG C. The device can be used for culturing nitrobacteria at low temperature, and the nitrobacteria content is up to 40-45%. The immobilized nitrobacteria have high low-temperature nitration resistance, and can treat the wastewater of which the ammonia nitrogen concentration is up to 1000 mg/L, so that the ammonia nitrogen in the wastewater is lowered to 1.0 mg/L or below.