This paper studies the resource allocation for multi-D2D (Device-to-Device) communications in heterogeneous networks with quality-of-service (QoS) guarantees for both cellular and D2D links. To improve the achievable rate of D2D communication and the spectrum utilization, one D2D pair is allowed to reuse multiple cellular spectrum resources. However, this scheme introduces more interference so that a proper resource allocation strategy is needed to control the interference and guarantee the QoS for communication links. We propose a novel algorithm to conduct the resource allocation, which is formulated as a mixed integer programming (MIP) problem. Then the optimality condition of the algorithm is analyzed. Numerical results reveal that our algorithm reduces the power consumption of D2D networks.