Metal‐organic frameworks (MOFs) are a class of porous coordination polymer. Recently, some studies have been focused on the detection of various analytes using luminescent MOFs. In this study, an MOF, Eu@1, is synthesized using ([Zn3(TAPB)2(CH3OH)2]) (1) as a precursor to encapsulate Eu3+. It has large pores and excellent luminescent properties, and the quantum yield is up to 30.2%, which can be used as a luminescent probe for highly selective Cu2+ sensing. It is simple and intuitive to use a lanthanide‐doped MOF for highly sensitive sensing of Cu2+ by the change of emitting color (from red to blue). The inductively coupled plasma (ICP) and X‐ray photoelectron spectroscopy (XPS) data indicate that Cu2+ can easily be exchanged with Eu3+ in 1D channels and replace a portion of the central ions. The good luminescent properties and visible color detectable to the naked eye demonstrate the potential application of this probe in colorimetric detection.