In this study, we propose a joint detection threshold optimization and transmit resource allocation algorithm for multiple-target tracking in radar network based on low probability of intercept (LPI). The basis of the proposed strategy is to jointly optimize the detection threshold and transmit resource, in order to minimize the total radiation power, while satisfying the constraints of the specified requirements on pre-defined target detection probability and tracking accuracy, as well as the given resource budgets. Furthermore, we derive the average target detection probability and Bayesian Cramér-Rao lower bound (BCRLB) arithmetic expressions within the associated gate, and respectively adopt them as the criterion function to evaluate the detection and tracking performance of radar network. By integrating semi-definite programming (SDP) and sequential quadratic programming (SQP) algorithm, we develop a three-step solution methodology to resolve the aforementioned optimization problem effectually. Through subsequent numerical simulations, we certify the superiority of our proposed algorithm in terms of resource consumption, outperforming existing approaches.