The aberrant expression of RNAs in ovarian cancer (OC) progression highlights their potential as clinical biomarkers. However, rapid and accurate quantification of these RNAs in biosamples remains a significant challenging. In this study, we develop a Modular Isothermal Rolling circle amplification (RCA)-Activated Cas12a Loop-Enhanced amplification (MIRACLE) method for circRNA and miRNA quantification without the need of reverse transcription. In this design, isothermal amplification of modular DNA can be initiated by target-specific RCA primers or miRNAs, with the amplification products subsequently recognized by the Cas12a system to generate measurable signals. When integrated with a multi-volume sliding chip (SlipChip) platform, this MIRACLE method enables portable, rapid and ultra-sensitive quantification of these two types of RNA. Under optimized conditions, this platform exhibits detection limits of 0.125 copies/μL for circRNA and 0.326 copies/μL for miRNA, covering a 5-log dynamic range from 10^-1 to 10³ copies/μL within 35 min. The platform was validated using OC cell lines and clinical blood samples. It successfully profiled OC RNA biomarkers (hsa_circ_0049101 and hsa-miR-338-3p), and effectively distinguishing between early and advanced stages of OC. These results show a strong correlation with RT-qPCR (R²=0.953 for circRNA and R²=0.947 for miRNA). This work establishes a versatile CRISPR-microfluidic platform for cancer diagnosis. Its modular design allows for adaptation to detect other cancer-related RNA biomarkers, thereby addressing critical needs in precision oncology.