A mobile ad hoc network (MANET) is an autonomous system of mobile platforms called nodes which are free to move around randomly and without constraint. The Communication in this type of network is subject to many security issues such as jamming attacks, identifying the jamming attacks are challenging, which can increase the security threats, so security has now become a fundamental requirement. This threat is the reason to do this study aims to propose a new anti-jamming strategy for MANET. we have proposed an anti-jamming technique which combines two techniques (FHSS and DSSS). to estimate the efficiency and efficacy of jammers; to validate the security metrics of MANET; and to enhance the performance of our anti-jamming strategy. And in order to confirm the improvements made by our technique, we carried out a simulation using the NS3 network simulator.