Scarcity of cultivated land resources and socioeconomic expansion have diversified cultivated land utilization modes. This research takes 183 county administrative units across Sichuan Province as research samples to build a three-dimensional (production, living, ecological) evaluation framework for cultivated land multifunctionality. Entropy weight method, multifunctionality index and sensitivity model are applied to quantify the spatiotemporal evolution of cultivated land functions across 2013–2023, and to detect the response intensity of multifunctionality to cultivated land quantity variation. Results indicate the following: (1) During 2013–2023, Sichuan’s cultivated land production function (PF) maintained stability, showing a contiguous east-high–west-low spatial pattern. The living function (LF) experienced moderate growth with scattered high–low values but shared identical spatial differentiation rules; the ecological function (EF) declined slightly with a decelerated decreasing rate in the late research phase, and its high- and sub-high-value areas agglomerated in the Eastern Sichuan Basin and mountainous area of Southwest Sichuan. (2) Provincial cultivated land area slightly increased initially then declined, yielding a slight total reduction while the overall spatial layout remained consistent. (3) Comparison between 2013–2018 and 2018–2023 reveals that production function sensitivity decreased sharply, LF sensitivity fell moderately, and ecological function sensitivity climbed upward. Investigations into spatiotemporal evolution and sensitive responses of cultivated land multifunctionality deliver vital theoretical and practical implications for mitigating conflicts between regional cultivated land protection and exploitation, as well as advancing efficient land resource allocation and coordinated promotion of multifunctions.