Does Huawei S2700 switch support PoE, and how much power?

Yes, some Huawei S2700 models can support PoE, for example S2700-26TP-PWR-EI and  S2700-9TP-PWR-EI.

There are two kinds of PoE power modules:

1, W0PSA2500: 250 W AC PoE Power Module

Switch chassis matching a 250 W AC PoE power module:

Supported only in the S2700-26TP-PWR-EI, S2700-52P-PWR-EI, and S2710-52P-PWR-SI

Appearance

2, W0PSA5000: 500 W AC PoE Power Module

Supported only in the S2700-26TP-PWR-EI, S2700-52P-PWR-EI, 

and S2710-52P-PWR-SI

Function:

PoE power supply

Input protection

Output protection

Overtemperature protection

Surge protection

Hot swap