This paper proposes a power allocation strategy for multi-target tracking in netted radar system under suppression jamming. The aim is to achieve better tracking accuracy with limited power. The information reduction factor is introduced in the posterior Cram\'{e}r–Rao lower bound (PCRLB) to indicate the uncertainty of the measurement caused by the jamming signal, which is a principal factor that makes the detection probability ($P_d$) being less than unity. This bound is used as the tracking performance metric. Then, a non-convex optimization problem regarding power allocation is established by minimizing the worst case tracking PCRLB. The gradient projection algorithm is used to solve the formulated problem. Finally, a closed-loop feedback framework is established by using the timely feedback results of target tracking to guide the subsequent power allocation. The simulation results verify the effectiveness of the performance metrics and the superiority of the proposed power allocation strategy.