Can I sign multiple sales contracts?

Of course. You can sign multiple sales contracts. Legal analysis: If you sign a contract with different parties on the same contract object, you may be liable for breach of contract because you can't fulfill your contractual obligations to one of them. There is no clear legal provision as to whether the contract should be made in duplicate. The parties may determine the number of contract copies according to the actual needs and the trading habits of both parties. If a written contract is adopted, it may be made in duplicate; If an oral contract is adopted, there is no need to make two copies.