A new design method for fire protection, based on analytic hierarchy process (AHP), was put forward, to explore an economic and secure strategy for fire protection of steel staggered-truss structure (SSTS). The chords and web members of SSTS were classified into different important grades by AHP according to the influence which components make on the stability of structure at elevated temperature. And the components are protected by different levels based on the important grades. Furthermore, a comparative investigation was conducted in order to appraise the economic and practical performance of the provided new fire protection method with traditional fire protection. The results indicate that the proposed fire protection strategy for SSTS based on AHP could achieve higher security with the same volume of fire retardant coatings.