Look over the schema of existing hybrid bicycle products, it usually costs hundreds of dollar and above one hour of installation since it requires the process to replace wheel or even asking to purchase a new bicycle. But in fact, it was not necessary to remove the original wheel because the key to achieve power drive could be taken as an external function adding to the primitive bike. Under the conditions of retaining applicability and safety that a transportation should never get rid of, this project was focusing on reducing budget and saving time of installation as much as possible by taking the power aid system as an external package to those existing bike which needs speed-up improvement. The solution would be a simple system including portable power resource, light weight motor with wide range of current acceptance, controlling device and gear chain drive. The further analysis to ensure safety and pursue this device to become capable to manufacture will be discussed in this proposal such as matchmaking the whole circuit without causing wear out and finding clever installation pattern for an ordinary users without any machinist knowledge nor sophisticated tools in hands. By combining these elements and testifying the suitability to majority of bicycle in the market, this project will become a very competitive product by the strength in its low cost of production and user-friendly installation.