<p>Deep and ultra-deep well drilling faces challenges of low rock-breaking efficiency and short bit life. This study optimizes novel convex-ribbed ridge PDC cutters to enhance drilling performance. Numerical simulations utilizing the orthogonal experiment design analyzed the effects of ridge angle (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(\alpha\)</EquationSource> <EquationSource Format="MATHML"><math> <mi>α</mi> </math></EquationSource> </InlineEquation>), ridge height (<InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(h\)</EquationSource> <EquationSource Format="MATHML"><math> <mi>h</mi> </math></EquationSource> </InlineEquation>), and fillet radius (<InlineEquation ID="IEq3"> <EquationSource Format="TEX">\(r\)</EquationSource> <EquationSource Format="MATHML"><math> <mi>r</mi> </math></EquationSource> </InlineEquation>) on mechanical specific energy (MSE). A systematic optimization strategy combining the Steepest Descent Method and Response Surface Methodology (RSM) was employed. The influence of the ridge angle (<InlineEquation ID="IEq4"> <EquationSource Format="TEX">\(\alpha\)</EquationSource> <EquationSource Format="MATHML"><math> <mi>α</mi> </math></EquationSource> </InlineEquation>) on the rock-breaking performance of the convex-ribbed ridge cutter was experimentally investigated. Results indicate the influence order on MSE is <InlineEquation ID="IEq5"> <EquationSource Format="TEX">\(\alpha\)</EquationSource> <EquationSource Format="MATHML"><math> <mi>α</mi> </math></EquationSource> </InlineEquation> &gt; <InlineEquation ID="IEq6"> <EquationSource Format="TEX">\(h\)</EquationSource> <EquationSource Format="MATHML"><math> <mi>h</mi> </math></EquationSource> </InlineEquation> &gt; <InlineEquation ID="IEq7"> <EquationSource Format="TEX">\(r\)</EquationSource> <EquationSource Format="MATHML"><math> <mi>r</mi> </math></EquationSource> </InlineEquation>. The optimal parameters were determined as <InlineEquation ID="IEq8"> <EquationSource Format="TEX">\(\alpha\)</EquationSource> <EquationSource Format="MATHML"><math> <mi>α</mi> </math></EquationSource> </InlineEquation> = 162°, <InlineEquation ID="IEq9"> <EquationSource Format="TEX">\(h\)</EquationSource> <EquationSource Format="MATHML"><math> <mi>h</mi> </math></EquationSource> </InlineEquation> = 0.4 mm, and <InlineEquation ID="IEq10"> <EquationSource Format="TEX">\(r\)</EquationSource> <EquationSource Format="MATHML"><math> <mi>r</mi> </math></EquationSource> </InlineEquation> = 3.8 mm. Comparative analysis shows the optimized cutter reduces MSE by 13.85% and significantly improves stability compared to conventional flat cutters. Field tests in heterogeneous carboniferous formations demonstrated that bits equipped with optimized cutters increased the rate of penetration (ROP) by 19%–85.7% and footage by 141.3%–237.2% compared to conventional bits. This study provides a rigorous optimization framework and effective tool solutions for hard-to-drill formations.</p>