The authenticity of the brand's gold can be checked by checking the trademark, checking the anti-counterfeiting code, and checking the packaging.

1. Check the trademark: The real Mengjinyuan jewelry trademark must be clear and free of blur, misalignment, mottled and other defects. If there is a problem with the trademark, it may be a fake.

2. Check the anti-counterfeiting code: Each Mengjinyuan jewelry product will have a unique anti-counterfeiting code. The authenticity can be checked through the Mengjinyuan Jewelry official website or the anti-counterfeiting query website.

3. Check the packaging: The packaging of real Mengjinyuan jewelry products is usually exquisite, with perfect details. If the packaging is loose and damaged, it may be a fake. You can also judge the authenticity of the purchased product by measuring the weight, size and other parameters of the jewelry and comparing it with the data on the Mengjinyuan official website.