The demand for in-vehicle communication services has increased the power consumption of base stations (BSs) and reduced the reliability of their data transmission. This paper presents a relay selection strategy for two-stage multicast transmission of vehicle security data (TSMT-VSD) under cellular networks. In this strategy

the selected relay range is first determined on the premise of saving total power consumption

and then the optimal multicast radius

x

0

with the lowest BS power consumption is calculated

followed by choosing the vehicle closest to the optimal multicast radius

x

0

as the rel

ay. Furthermore

based on the social attributes of relays

an asymmetric evolutionary game model between BS groups and relay groups is established

and a reward and punishment mechanism for dynamic redistribution of relay entertainment data transmission power without affecting secure data transmission is designed. The simulation results show that the proposed relay selection strategy and the designed reward and punishment mechanism can not only ensure the reliability of TSMT-VSD

but also save at least 25% power consumption of BS compared with the conventional one-stage multicast transmission

provided that the number of vehicles is beyond the bound

K

min

.