Biomass alternative fuels have been around the world attention. This paper studies the characteristics of bio-diesel, bio-diesel by analyzing the physical, chemical properties, comparative bio-diesel and military advantages and disadvantages of diesel fuel come to bio-diesel is a diesel engine available in alternative fuels. In order to verify the heavy-duty off-road vehicles and light army vessel used biodiesel economy, power and reliability, we use the MAN-B & W6L20(27) diesel engine on the practical application of bio-diesel experiment results showed that: the security, power, oil consumption, emissions and reliability of all the available fuel to reach the target, it can be used as a safe alternative fuel use in diesel engines.