本文用X射线衍射分析法、金相分析法、电子探针显微分析法,研究和测定了Cu-Y-Si三元系合金相图的室温截面。它包含有17个单相区、33个两相区、17个三相区。ε、ρ、φ、ψ、θ、ζ、τ、ω共八个单相均无可察觉的固溶度。此截面中出现了两个成分固定的新相π、μ。 In this paper, X-ray diffraction analysis, metallographic analysis, electron probe microanalysis method to study and determine the Cu-Y-Si ternary alloy phase diagram at room temperature section. It contains 17 single-phase zone, 33 two-phase zone, 17 three-phase zone. There are no detectable solid solubility of eight single-phase in ε, ρ, φ, ψ, θ, ζ, τ, ω. There are two new phases π, μ with fixed composition in this section.