To Decorater
If you are found to have crashes, I'm sorry, you can follow the previous suggestion to use python_d.exe then open a new issue uploading crash dump.
It would be better.

About the multiprocessing question，I would like to add some information.

My code uses a multiprocessing Pool，I used multiprocessing.util.debug opened the debug information.debug information is as follows.

[DEBUG/SpawnPoolWorker-7] thread 'MainThread' does not own a connection
[DEBUG/SpawnPoolWorker-7] making connection to manager
[DEBUG/SyncManager-2] starting server thread to service 'SpawnPoolWorker-7'
[INFO/SpawnPoolWorker-4] test:lock:token: Token(typeid='Lock', address='\\\\.\\pipe\\pyc-3816-0-95051ql_', id='e44c9bc720')
[INFO/SpawnPoolWorker-4] test:lock:handle: 712
[INFO/SpawnPoolWorker-7] test:lock:token: Token(typeid='Lock', address='\\\\.\\pipe\\pyc-3816-0-95051ql_', id='e44c9bc720')
[INFO/SpawnPoolWorker-7] test:lock:handle: 768
[DEBUG/SpawnPoolWorker-7] DECREF 'e44c9bc720'
[INFO/SpawnPoolWorker-4] leave:lock:token: Token(typeid='Lock', address='\\\\.\\pipe\\pyc-3816-0-95051ql_', id='e44c9bc720')
[DEBUG/SpawnPoolWorker-7] thread 'MainThread' has no more proxies so closing conn
[DEBUG/SpawnPoolWorker-7] DECREF 'b0182059f8'
[DEBUG/SyncManager-2] got EOF -- exiting thread serving 'SpawnPoolWorker-7'
[DEBUG/SpawnPoolWorker-4] INCREF 'e44c9bc720'
handle is closed
'ForkAwareLocal' object has no attribute 'connection'
[DEBUG/SpawnPoolWorker-7] thread 'MainThread' has no more proxies so closing conn
Traceback (most recent call last):
  File "C:/Users/Administrator/Desktop/Monitor_URL\Monitor_SQL.py", line 51, in execute_select_command
    conn.close()
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python35\lib\multiprocessing\managers.py", line 949, in __exit__
    return self._callmethod('release')
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python35\lib\multiprocessing\managers.py", line 716, in _callmethod
    conn.send((self._id, methodname, args, kwds))
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python35\lib\multiprocessing\connection.py", line 204, in send
    self._check_closed()
  File "C:\Users\Administrator\AppData\Local\Programs\Python\Python35\lib\multiprocessing\connection.py", line 136, in _check_closed
    raise OSError("handle is closed")
OSError: handle is closed
[INFO/SpawnPoolWorker-7] Exception:lock:token: Token(typeid='Lock', address='\\\\.\\pipe\\pyc-3816-0-95051ql_', id='e44c9bc720')
[INFO/SpawnPoolWorker-7] Exception process:lock:token: Token(typeid='Lock', address='\\\\.\\pipe\\pyc-3816-0-95051ql_', id='e44c9bc720')
[DEBUG/SyncManager-1] got EOF -- exiting thread serving 'SpawnPoolWorker-7'
[DEBUG/SpawnPoolWorker-4] INCREF 'b0182059f8'
[DEBUG/SpawnPoolWorker-4] DECREF 'b0182059f8'
[DEBUG/SpawnPoolWorker-7] INCREF 'e44c9bc720'

This time the message and not the same，From the information looks like two processes simultaneously locking the same lock object, and then release happened the problems.I do not know if this is correct，
But i will continue to follow the issue.