The Speaking Skill Evaluation (SSE) technologies are derived from speech recognition technologies and are used for language learning and instructing. In this paper, an effective automatic pronunciation scoring method for SSE systems is proposed. The Center-Distance Continuous Probability Model (CDCPM) is incorporated to model the speech. The Merging-Based Syllable Detection Automaton (MBSDA) and the Non-Linear Partition (NLP) method are used to perform the time alignment. And the Critical Area Percentage (CAP) based scoring method is used to score the learner’s pronunciations or reject invalid utterances. Subjective assessments show that this method is concise, fast, and effective. The SSE system based on it has achieved a satisfying performance.