Using mathematical and economical methods,starting from studying normal penalty benefit maths model,we have set up penalty benefit model of preventing offence about escaping from traffic accident.

Penalty benefit is the due punitive effect to the criminals and the effect of forcing people not to commit a crime or not to commit a new crime obtained by the country employing penal cost: the formulation of punishment, compulsory force of punishment and actual application and implementation of punishment.

The kernel thoughts of the science of economic analysis law are the beneficial results of law, and the research of the beneficial results of penalty is based on the former.

This article carefully examines the penalty from the criminology angle of view,elaborated the penalty potency and the crime school of thought,the penalty potency and the crime benefit,the restricted factors of the penalty potency realization.