With the rapid growth of video streaming services, content providers (CPs) face significant challenges in efficiently delivering multimedia content via heterogeneous content delivery network(CDN) nodes. Resource allocation and pricing strategies that overlook node heterogeneity and information asymmetry often result in inefficient utilization and degraded service quality. To address these issues, we propose a contract-theoretic incentive mechanism that enables the CP to design differentiated resource–reward bundles. These bundles satisfy individual rationality (IR) and incentive compatibility (IC) constraints, allowing CDN nodes to voluntarily select optimal contracts based on their private information. We derive the conditions for feasible contract design and develop an optimization framework to maximize social welfare. Extensive simulations demonstrate that the proposed mechanism significantly outperforms baseline strategies such as linear pricing and random contract assignment, yielding notable gains in social welfare, CP utility, and CDN node participation. This work provides new insights into efficient and incentive-compatible content caching for heterogeneous video streaming delivery networks.