High entropy compounds have a well-defined lattice in high symmetry, however, there are strong local distortion due to the size difference among various elements. Recently, superconductivity has been reported in high entropy alloys, carbides and silicates. In most high entropy compounds, it has a relative low Tc. Here, we demonstrate a record-high Tc in a high entropy alloy TaNbHfZr, reaching 15.3 K by pressure engineering. The magnetic field dependence of the critical temperature fitted by the Ginzburg-Landau formula suggests the highest upper critical magnetic field is around 16.3 T at zero temperature. Meanwhile the relation between Tc and pressure shows a dome-shape, suggesting a competition behavior. First-principles calculations attribute the dome-shaped curve to two competing effects, that is, the enhancement of the logarithmically averaged characteristic phonon frequency ω_log and the simultaneous suppression of the electron-phonon coupling constant λ. Thus, TaNbHfZr may have a promising future for studying the underlying quantum physics, as well as developing new applications under extreme conditions. In addition, we observe the coexistence of superconductivity and ferromagnetism in high entropy carbides, which makes high entropy carbides a promising future for multifunctional application.
 

Superconductivity，,high entropy