To succeed on the aim of achieving a carbon-neutral energy system, improving the efficiency of waste heat recovery is an important technique route. However, most of available heat sources in energy-intensive industries and transport sectors always present fluctuating nature that prohibits the safe and efficient operation of organic Rankine cycle (ORC) based waste heat recovery systems. Hereby, this study proposes a novel ORC system integrated with latent thermal energy storage (LTES), using LTES to reduce the thermal power fluctuations of engine exhaust and improve the safety performance of downstream ORC system. A dual-model test bench including the traditional basic ORC and ORC-LTES directly driven by engine exhaust is designed and established. The dynamic performance of basic ORC and ORC-LTES is experimentally investigated and compared under different step-change and cyclic engine conditions. The experimental results indicate that the existing of LTES can significantly reduce the fluctuating range of exhaust temperature at the evaporator inlet under both step-change and cyclic engine conditions. Under step-change engine conditions, ORC-LTES can completely resist the sudden reduction of exhaust temperature and mass flowrate under small step-change ratio of engine load, and the superheat degree of ORC-LTES lasts much longer time to drop to zero than the basic ORC under larger step-change ratio of engine load, while superheat degree of the basic ORC fast drops to zero under different step-change engine conditions. Under cyclic engine condition, ORC-LTES keeps safely operating all the time while the basic ORC has to stop working in each period, in addition, the net power and thermal efficiency of ORC-LTES are 23.5% and 23.2% higher than that of the basic ORC respectively. •A novel ORC system integrating with latent thermal energy storage is proposed 79.•A dual-mode ORC test rig driven by transient engine exhaust is designed and built.•Different step-change and cyclic engine operating conditions are considered.•Dynamic performance of basic ORC and proposed ORC-LTES are experimentally compared.•Net power and thermal efficiency of ORC-LTES are 23.5% and 23.2% higher than basic ORC.