At present

the blockchain technology is rising all over the world

accelerating the application to the securities market

payment systems

notes and supply chain finance

customer credit and anti fraud

digital asset management and other fi elds.But as an emerging technology

its security risks can not be ignored.In this paper

we analysis the challenge and safety risk of the blockchain technolog based on the safety characteristics of it

and propose some countermeasures

and then some suggestions for the development of blockchain industry are given.