When the instantaneous thermal load is too large or the partial overheating occurs in the evaporator, loop heat pipe is prone to failure. In order to make the failing loop heat pipe back to proper functioning as early as possible, the feasibility of two restart schemes after loop heat pipe fail and the factors affecting restarting speed were researched. The experimental results shows that reheating evaporator in the recover process after failure makes loop heat pipe restart to reduce recover time. Gravity and heating power are the key factors affecting restart speed. When the heating power is small, the restart speed under gravity assistance is much faster than the restart speed under antigravity. With the increasing of the heating power, effect of gravity factor on restart speed of loop heat pipe diminishes gradually. Loop heat pipe can also stop failure by lifting the condenser without cutting the heating power off. However, this scheme is not feasible because the reverse flow occurs in loop heat pipe.