How to deal with the travel expenses of travel agencies that sign up for terrorist attacks in France?

I haven't heard of any tour group canceling its trip in China because of the French terrorist attacks.

If the travel agency informs you to cancel your trip, it is because of the terrorist attacks in France. I suggest you ask other local travel agencies to see if they have also cancelled their trip to France. Because it seems that the Ministry of Foreign Affairs of China hasn't issued an early warning of French tourism, I don't know why your group will be cancelled. If the terrorist incident in France is just an excuse for the travel agency to cancel the group tour, then the travel agency has breached the contract and they need compensation.

If the trip is cancelled because of the terrorist incident in France, then you can only share the loss according to the signed travel contract, and there is a trip cancellation caused by force majeure. See the contract for specific terms.