Yes, the Huawei 27W wireless Fast charger can charge the Mi 9. Although Huawei and Xiaomi are different brands, they both follow the Qi wireless charging standard, so compatibility is there. The Huawei 27W Wireless Fast Charge has a high power output, which can provide a fast charging experience for the Mi 9, allowing your phone to recover power faster. No need to worry about the compatibility of the charger, you can rest assured to use Huawei 27W wireless fast charge to charge the Mi 9.
Yes, it has a bit more charging power than this, but it can be used backwards compatible and the charging speed will be slower.