Quote from: ywnasdzkd on Today at 09:42:02 AM

Here are some questions about the node deployment of Bitcoin. I hope you can help me. Thanks.

Question 1
-connect=<ip>
Connect only to the specified node; -noconnect disables automatic connections (the rules for this peer are the same as for -addnode). This option can be specified multiple times to connect to multiple nodes.

The above is a description of Bitcoin connection options. What is the maximum number of times the connection is used？in other words，How many nodes can a node connect at the same time？

The default number of connections (nodes) Bitcoin Core works with is 125: 10 outbound and 115 inbound.
This number is big - leads to a lot of traffic - and, depending on your internet plan you may want to adjust.
Normally the peer nodes are "harvested" from the network, but you can add with addnode "fallback nodes" you may want to be sure you connect to.
From the way I understand these numbers, I think that the answer to your intended question may be 10.

Quote from: ywnasdzkd on Today at 09:42:02 AM

Question 2
If I have an IP address of a node, can I obtain the IP addresses of all nodes connected to this node？

Nope.