If you have a Windows 10 installation media (USB or DVD), you can use the Deployment Image Servicing and Management (DISM) tool to install the language pack offline.
It is structured to be user-friendly, addressing both the "direct download" method (using CAB files) and the "easy transfer" method (using an online PC to get the files for an offline PC). windows 10 chinese language pack offline download
You may find websites offering direct downloads for .cab files (e.g., Windows10_Chinese_Language_Pack.cab ). Be extremely cautious. These files are often hosted on third-party "driver" sites and can contain malware or be incompatible with your specific Windows build version. If you have a Windows 10 installation media