In this study, a cloud service optimisation model is presented for resource adaptation control, in which the cost to the user, various levels of virtual machine efficacy, and rental price are considered. A cloud service middleware that supports flexible web services by using heterogeneous platforms is proposed. Developers can conveniently register web services and deploy them to the middleware. The middleware provides an energy-minimisation load balance (EM-LB) mechanism, which considers the temperature of the machine, its power consumption, and the computing resources of virtual machines. The EM-LB mechanism maintains a safe temperature threshold and minimises power usage, thereby reducing hotspots and conserving energy. Furthermore, a two-stage cloud service optimisation model is proposed to analyse users’ requirements and existed computing resources for finding the Pareto optimality, and the aspirational level is found in accordance with the Pareto optimality for the lower cost and lower execution time. The simulation results show the efficiency of the proposed cloud service optimisation model and EM-LB mechanism. Finally, the proposed EM-LB mechanism is implemented to prove the feasibility of the model.