In order to solve the problems of high outage probability and unbalanced load in dense small cellular networks, an energy-efficient scheme based on load balancing was proposed. The network energy-efficiency was maximized through joint optimization of load balancing and base station on/off control strategy under the constraints of guaranteed user outage probability and minimum rate. The optimization problem is a non-convex Non-deterministic Polynomial-hard (NP-hard) problem, and it is quite complex to obtain the optimal solution. Therefore, the original optimal problem was decomposed into two suboptimal subproblems. Firstly, the optimal load balancing strategy with the given base station on/off control strategy was given by the proposed load balancing scheme. Secondly, the optimal base station on/off control strategy was designed under the constraint of satisfying the minimum user rate. The experimental results show that, when the number of users is less than 180, the outage probability of the proposed scheme is zero while the outage probability of the traditional Maximum Signal to Interference plus Noise Ratio (Max-SINR) algorithm reaches 11%. The network energy-efficiency of the proposed scheme is higher than those of the base station Randomly-off (Ran-off) algorithm and the base station Not-off (No-off) algorithm. The proposed scheme can improve network energy-efficiency and ensure load balance.