The invention relates to a method for developing ultra-low permeability reservoir by combining vertical well volume fracturing and line flooding. The method at least comprises the following steps that 1, a rectangular five-spot flood system is formed, oil production lines and water injection lines are formed in the rectangular five-spot flood system, the oil production lines and the water injection lines are mutually parallel and arranged in a staggered mode, and the extension direction of the oil production lines and the water injection lines is parallel to the maximum parallel principal stress direction; 2, volume fracturing is conducted on production wells and water injection wells in sequence, injection of flow lines between the oil production lines and the water injection lines is made to form a straight line on a horizontal plane. The flow lines are water flooding flow lines, namely, water flooding channels, formed between the water injection lines and the oil production lines. According to the method, an efficient driving system is established between the water injection lines and the oil production lines, the water injection capacity is enhanced, the oil well single well yield is greatly increased, and the oil production rate and the final water flooding recovery efficiency are increased.