Hey can anyone suggest me that which SSD card will be suitable for my dell Vostro 3470 SFF. i bought a SSD nvme but it is not working in my pc so plz reply me.

This system supports one M.2 SATA drive - it does not support NVMe.

Correct The M.2 slot in this model only supports M.2 sata ssd per spec, not M.2 nvme ssd, but you can use a PCIe adapter to run M.2 nvme ssd. For SFF change to short bracket included.