This paper develops a theoretical and empirical framework to analyze China's interest rate corridor, focusing on the Standing Lending Facility (SLF). We construct a general equilibrium model featuring an explicit corridor and a novel accessibility cost friction (α), which captures implicit costs during SLF application. The theoretical properties of the model explain key stylized facts associated with the corridor operation. The study highlights several fundamental properties of the corridor as a policy framework: 1) Both the width and the midpoint of the corridor are active policy tools, implying that SLF and Interest on Excess Reserves (IOER) policies should be designed cohesively within the unified corridor framework; 2) The policy's efficiency varies with the level of market liquidity; and 3) The corridor framework allows for a separation between price-based and quantity-based monetary policy instruments. Empirically, we employ the Joint Power Prior (JPP) Bayesian estimation to quantify the α time series, identifying structural breakpoints that align with major policy and market events. This study provides a quantitative tool for monitoring SLF transmission efficiency.