The invention discloses a pressure test medium bidirectional flow pressure control method and belongs to the technical field of hydraulic tests. According to the method, for a pressure boost control process, a piston of a pressure control pipeline A or of a pressure control pipeline B is controlled for realizing pressure boost for a tested container, if failure of target pressure occurs, the pressure control pipeline A and the pressure control pipeline B are controlled for realizing alternate pressure boost; for a pressure keeping control process, after the target pressure is realized, when constant pressure keeping is required, a water outgoing stop valve is not closed, a water incoming stop valve is closed, the pistons of the pressure control pipeline A and the pressure control pipeline B are controlled for realizing individual or simultaneous backwards and forwards movement to realize constant pressure requirements; for a pressure reduction control process, the piston of the pressure control pipeline A or of the pressure control pipeline B is controlled for realizing pressure reduction for the tested container, if failure of target pressure occurs, the pressure control pipeline A and the pressure control pipeline B are controlled for realizing alternate motion, continuous uninterrupted pressure reduction can be realized in a pressure reduction process, and a purpose of pressure reduction control is realized. The method is advantaged in that a pressure boost rate and a pressure reduction rate can be effectively controlled, and control precision can reach +/-0.02MPa.