Both standards have different objectives. ISO 31000 is a standard that gives you a guide of best practices for the risk management (any type of risks: information security, environmental, financial, etc). On the other hand, ISO 22301 establishes requirements for the implementation of a Business Continuity Management System, where you need to management risks to avoid interruptions of the business continuity. So, for the implementation of the ISO 22301, you can use the ISO 31000 (but it is not mandatory). Anyway, there is another ISO also related to risks: ISO 27001, which core is the risk management (although only for information security), and in this case there is another guide of best practices focused on information security: ISO 27005 (has the same structure that the ISO 31000).