Remote quantitative laser-induced breakdown spectroscopy (LIBS) of nuclear fuel materials is a challenging task due to unstable laser delivery and limited plasma emission collection stability. Establishing robust fiber-optic LIBS (FO-LIBS) systems with optimal operational stability is demanding. This study develops a high-throughput FO-LIBS system for quantitative analysis of CeO?-based surrogate nuclear fuel. It incorporates a 10 m, 1 mm core multimode silica delivery fiber, a compact flat-top focusing probe, and a six-channel off-axis emission collection module with a broadband (180–900 nm) detection system. Beam profiling demonstrated that the incident Gaussian beam was transformed into a homogenized flat-top profile after fiber transmission, resulting in improved plasma stability and repeatability. Over 100 consecutive shots, the system achieved a transmission efficiency of approximately 54% with pulse energy variations of less than 2%. The full-spectrum had a relative standard deviation (RSD) of less than 5%. Internal standard normalization using Ce II emission lines produced highly linear calibration curves for La I and Nd II transitions (R2 > 0.99). These findings indicate that the developed FO-LIBS system displayed stable and reproducible quantitative performance, while its detachable probe configuration provides potential flexibility for remote analysis across multiple hot cells in radiation constrained environments.