The invention discloses an analog counting circuit with a high counting range applied to a single photon avalanche diode (SPAD) detector. The circuit is composed of a counting capacitor C, a resistor R and fifteen MOS transistors, wherein a Cascode biasing circuit is formed by the NMOS transistors MN3 and MN4, the PMOS transistors MP6, MP7, MP8 and MP9, and the resistor R for providing bias for the counting circuit; meanwhile, the biasing circuit also provides a current source load for an output follower of the counting circuit, so that linear output of a counter is ensured; the biasing circuit also provides a biasing voltage with high level for the current-limiting PMOS transistor, thus playing a role in preventing the breakover current from being excessive on a charging branch of the counting capacitor. The invention also provides a counting method by using the analog counting circuit with the high counting range applied to the SPAD detector. The method comprises three stages consisting of a resetting stage, a counting stage and a reading stage. The analog counting circuit provided by the invention can reduce capacitor area and is large in counting range, and also has the advantage of high filling coefficient of a pixel unit.