The water industry control systems have stringent requirements for security and stability，and some cybersecurity tasks are not suitable to be directly implemented in the production environment. As an important tool for research on industrial control system cybersecurity，a testbed can validate the effectiveness of cybersecurity tasks and their impact on production continuity in a non-production environment. This paper proposes a flexible testbed construction method that allows for the adjustment of hardware connections and process scenarios via software，enabling a single testbed to deploy multiple business scenarios in a time-sharing manner，thereby significantly enhancing the testbed's application value. Simulation results show that conducting vulnerability mining，penetration testing，and effectiveness testing of security solutions for industrial control systems based on this testbed can effectively advance the practical application of cybersecurity tasks in the water industry.