Axiomatic Design is one of the most widely used design method at present, and it is a structural design method. This design method is highly valued by designers. Axiomatic Design can form a rational design scheme and provide criteria and assessment methods. There are two basic axioms: independence axiom and information axiom. With the rapid development of shipping, ship security has becomes the focus of concern. Oil tanker safety is even more important. Balance pressure proportioning set is one of the most popular products in its class. It’s advantages are high reliability, high flow range, big foam liquid storage capacity. These advantages make it a ideal fire-fighting equipment for oil tanker. Based on Axiomatic Design, it is given that a rational design method for balance pressure proportioning set. This activity will have a profound impact on fire-fighting equipment research.