之前一直出现：
Failed to connect to the database: could not connect to server: Connection refused
Is the server running on host "localhost" (::1) and accepting TCP/IP connections on port 5432?今天用msfdb的命令查询了一下，才知道需要输入msfdb start才行。 
输入
msfdb start
然后输入msfconsole即可。
msfconsole