The strategies of portfolio insurance are introduced according to its principles and design thinking.The(authors) give the simple mathematical models and practical processes of option-based portfolio insurance(OBPI),constant mix(CM),constant proportion portfolio insurance(CPPI),and time-invariant portfolio protection(TIPP),and use risky assets containing 180 index's stocks of Shang-hai Stock Exchange and risky-free assets containing bonds to form portfolio to do empirical simulating.Based on the results,they analyze the above strategies comparatively,gives the(related) investment suggestion,and shows how to avoid risk without restriction on profit.