The explosion heat (Q_v), the combustion temperature(T_f) and the combustion gas generation rate(η) of boron based fuel-rich propellant contained Mg, Al and magnalium were tested to comparatively study the effects of the metal on its combustion. Results show that Mg improves Q_v, T_f, η of propellant better than Al, and the magnalium decreases the Q_v, T_f, but increases η higher than Mg. Compared with moderately boron, the coarse or fine boron increases the Q_v, T_f higher, and decrease the η lower. The explosion heat, the gas generation rate decrease and the combustion temperature increases with the increasing of the boron content.