Apply for a two-year multiple-entry visa at the Singapore Embassy in China. Stay for 3 days at a time, then go to nearby Indonesia for 1-2 days (Indonesia is landing visa), and then come back for another 3 days.
First of all, please ask your relatives and friends in Singapore to apply to the Singapore Immigration Bureau. When applying, you need many application materials such as credit card guarantee and valid certificate guarantee.
2. You can get a claim document within 1-3 days after the application. You can exchange this document with the Singapore Immigration Bureau for a white card for visiting relatives and send it back to China.
If you apply in China, you need to provide invitations and letters of guarantee from friends and relatives in Singapore, and then go to the Singapore Embassy in China to apply. Generally speaking, you can get a visa in the afternoon after submitting your application in the morning.