Exhibit 15.3

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the following Registration Statements:

1) Registration Statement (Form S-8 No. 333-172962) pertaining to the 2007, 2008 and 2010 Stock Incentive Plans of ChinaCache International Holdings Ltd.,

2) Registration Statement (Form S-8 No. 333-176751) pertaining to the 2011 Share Incentive Plan of ChinaCache International Holdings Ltd., and

3) Registration Statement (Form F-3 No. 333-195192) and related prospectus of ChinaCache International Holdings Ltd.;

of our report dated April 30, 2018, with respect to the consolidated financial statements of ChinaCache International Holdings Ltd. included in this Annual Report (Form 20-F) of ChinaCache International Holdings Ltd. for the year ended December 31, 2017.

/s/ Ernst & Young Hua Ming LLP

Shanghai, the People’s Republic of China

April 30, 2018